Bendix Sd 01 3131 Users Manual

2015-04-02

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PRODUCT

This Bendix® 720cc twin cylinder compressor is a “discharge

line unloader” DLU-style compressor. The compressor

pumps continuously, unlike some compressor designs

which use an "unloader" mechanism in the compressor

head to switch from a pumping mode to a non-pumping

mode. With a DLU-style compressor, the control of air

delivery to the vehicle’s air system is managed by using a

separate discharge line unloader valve mounted in parallel

with a turbo cut-off-style air dryer (see Figure 6).

DESCRIPTION

The function of the air compressor is to provide and

maintain air, under pressure, to operate devices in air brake

systems. The Bendix 720cc compressor is a twin cylinder

reciprocating compressor with a rated displacement of 31.6

cubic feet per minute at 1250 RPM.

The compressor consists of an integral water-cooled

cylinder head assembly and water-cooled crankcase.

The cylinder head assembly is made up of an aluminum

cylinder head, an aluminum cooling plate, and a cast

iron valve plate assembly. It uses two sealing gaskets.

The cylinder head contains air and water ports. A cooling

plate is located between the cylinder head and valve plate

assemblies and assists in cooling.

The valve plate assembly consists of brazed cast iron

plates which have valve openings and passages for air and

engine coolant to ow into, and out of, the cylinder head and

crankcase water jacket. The compressor discharge valves

SD-01-3131

BENDIX® 720CC TWIN CYLINDER COMPRESSOR FOR

INTERNATIONAL® MAXXFORCE® BIG BORE ENGINES

MAXXFORCE® is a trademark of International Engine Intellectual Property Company, LLC.

FIGURE 1 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR

FIGURE 2 - NAMEPLATES

Bendix Part Number . . . . . . A

Customer Part Number. . . . . B

Compressor Serial Number . . C

720cc COMPRESSOR

BENDIX PRODUCT - ASSY IN FRANCE

BENDIX

P/N

NAV

P/N

Safety

Valve

Cooling

Plate

Cylinder

Head

Valve Plate

Assembly

Locating

Pins

Crankcase

Mounting

Face

Rear

Flange

Right Side

View

GENERAL SAFETY GUIDELINES

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS

TO AVOID PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES:

▲ Park the vehicle on a level surface, apply the

parking brakes and always block the wheels.

Always wear personal protection equipment.

▲Stop the engine and remove the ignition key

when working under or around the vehicle.

When working in the engine compartment,

the engine should be shut off and the ignition

key should be removed. Where circumstances

require that the engine be in operation, EXTREME

CAUTION should be used to prevent personal

injury resulting from contact with moving,

rotating, leaking, heated or electrically-charged

components.

▲Do not attempt to install, remove, disassemble

or assemble a component until you have read,

and thoroughly understand, the recommended

procedures. Use only the proper tools and

observe all precautions pertaining to use of those

tools.

▲If the work is being performed on the vehicle’s

air brake system, or any auxiliary pressurized air

systems, make certain to drain the air pressure

from all reservoirs before beginning ANY work

on the vehicle. If the vehicle is equipped with a

Bendix® AD-IS® air dryer system, a Bendix® DRM™

dryer reservoir module, or a Bendix® AD-9si™ air

dryer, be sure to drain the purge reservoir.

▲ Following the vehicle manufacturer’s

recommended procedures, deactivate the

electrical system in a manner that safely removes

all electrical power from the vehicle.

▲Never exceed manufacturer’s recommended

pressures.

▲Never connect or disconnect a hose or line

containing pressure; it may whip. Never remove

a component or plug unless you are certain all

system pressure has been depleted.

▲ Use only genuine Bendix® brand replacement

parts, components and kits. Replacement

hardware, tubing, hose,  ttings, etc. must be of

equivalent size, type and strength as original

equipment and be designed speci cally for such

applications and systems.

▲Components with stripped threads or damaged

parts should be replaced rather than repaired.

Do not attempt repairs requiring machining or

welding unless speci cally stated and approved

by the vehicle and component manufacturer.

▲Prior to returning the vehicle to service, make

certain all components and systems are restored

to their proper operating condition.

▲ For vehicles with Automatic Traction Control

(ATC), the ATC function must be disabled (ATC

indicator lamp should be ON) prior to performing

any vehicle maintenance where one or more

wheels on a drive axle are lifted off the ground

and moving.

▲The power MUST be temporarily disconnected

from the radar sensor whenever any tests USING

A DYNAMOMETER are conducted on a Bendix®

Wingman® Advanced™-equipped vehicle.

▲ You should consult the vehicle manufacturer's operating and service manuals, and any related literature,

in conjunction with the Guidelines above.

are part of the valve plate assembly. The inlet reed valve/

gasket is installed between the valve plate assembly and

the top of the crankcase.

The cast iron crankcase has a water jacket to assist in the

cooling of the cylinder bore. The crankcase has an open

side with a machined face and locating pins. This open face

is bolted directly to the side of the engine block. Refer to

Figure 3.

The compressor gear engages the engine drive gear.

In addition, the crankcase houses the piston assembly,

connecting rod, crankshaft and related bearings. O-rings

are located in the countersunk holes (one each side) on

the crankcase deck to prevent coolant leakage between

the crankcase and valve plate coolant passage.

The Bendix® 720cc compressor is equipped with a safety

valve to protect the compressor head in the event of, for

example, a discharge line blockage downstream of the

compressor. Excessive air pressure will cause the safety

valve to unseat, release air pressure, and give an audible

alert to the operator. The safety valve is installed in the

cylinder head safety valve port, directly connected to the

cylinder head discharge port.

A nameplate is attached to a at cast face on the side of

the crankcase. It is stamped with information identifying the

compressor model, customer piece number, compressor

assembly part number and serial number. See Figure 2.

FIGURE 3 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR

Compressor to

engine block

mounting face

Oil drain locations

Safety

Valve

Cooling

Plate

Valve Plate

Assembly

Cylinder

Head

Crankcase

Drive Gear

Nameplate

Piston

Crankshaft

Mounting

Face

Connecting

Rod

OPERATION

The compressor is driven by the vehicle's engine, and

functions continuously while the engine is in operation.

Actual compression of air is controlled by a downstream

component – like a discharge line unloader valve, or an air

dryer without turbo cut-off valve – operating in conjunction

with a governor.

AIR INTAKE (LOADED)

Just as the piston begins the down stroke, (a position known

as Top Dead Center, or TDC), the vacuum created in the

cylinder bore above the piston causes the inlet reed valve to

ex open. Atmospheric air ows through the open inlet valve

and lls the cylinder bore above the piston. See Figure 4.

AIR COMPRESSION (LOADED)

When the piston reaches the bottom of the stroke, (a

position known as Bottom Dead Center, or BDC), the inlet

reed valve closes. Air above the piston is trapped by the

closed inlet reed valve and is compressed as the piston

moves upwards. When air in the cylinder bore reaches

a pressure greater than that of the system pressure, the

discharge reed valves open and allow air to ow into the

discharge line and air brake system. See Figure 5.

FIGURE 6 - TYPICAL BENDIX® 720CC (DLU-STYLE) TWIN CYLINDER COMPRESSOR AIR CHARGING SYSTEM

UNL

RES

21 22

UNL

Compressor

Governor

Air Dryer

Front Service

Reservoir

Rear Service

Reservoir

DLU Valve

FIGURE 5 - OPERATION - COMPRESSION

Piston Moving Up

Air Inlet

Port

Inlet

Valve

Closed

Air

Discharge

Port

Discharge

Valve

Open

Valve

Plate

Cooling

Plate

FIGURE 4 - OPERATION - INTAKE

Piston Moving Down

Air Inlet

Port

Inlet

Valve

Open

Air

Discharge

Port

Discharge

Valve

Closed

Valve

Plate

Cooling

Plate

NON-COMPRESSION OF AIR (UNLOADED)

COMPRESSOR AND AIR DRYER SYSTEM

(REFER TO FIGURE 6)

Air delivery to the vehicle’s air system is controlled either

by the governor and the air dryer, or with a separate

discharge line unloader valve. The governor is plumbed

to the component (e.g. air dryer or DLU valve) in order to

control when the air is delivered to the vehicles air system.

When air pressure in the supply reservoir reaches the cut-

out setting of the governor, the governor delivers system air

to the discharge line unloader style (DLU) air dryer’s control

port. This allows the discharge air from the compressor to

ow out the exhaust port of the air dryer.

Note: The Bendix® 720cc compressor is a discharge

line unloader-style (DLU-style) unit. This means that the

compressor functions in a continuous pumping mode;

regardless of whether the brake system requires air. It

requires a downstream device (e.g. turbo cut-off-style air

dryer and discharge line unloader valve) to unload the

system when air requirements have been met as described

in the previous paragraph.

LUBRICATION

The vehicle's engine provides a continuous supply of oil

to the compressor. Oil is routed from the engine to the

compressor's oil inlet. Note: There is no external oil supply

line; the oil delivery is located at the engine to compressor

mounting face. (See Figure 7.) This pressurized oil ows

to the precision front sleeve main bearing, and — via an oil

passage in the crankshaft — routes pressurized oil to the

connecting rod bearings and the rear journal associated

with the end cover. Spray lubrication of the cylinder bore

and connecting rod wrist pin bushing is obtained as oil is

forced out around the crankshaft journals by engine oil

pressure. Oil then falls to the bottom of the compressor

crankcase and is returned to the engine through the

opening at the compressor mounting ange.

COOLING

The Bendix 720cc twin cylinder compressor is cooled both

by air owing through the engine compartment as it passes

the compressor's cast-in cooling ns, and by the ow of

engine coolant through the cylinder head assembly and

the water jacket around the cylinder bore of the crankcase.

Coolant supplied by the engine cooling system passes

through connecting lines into the cylinder head, cooling

plate, valve plate assembly, and into the crankcase water

jacket. It returns through the same components — out of

the coolant outlet port of the cylinder head — and returns

to the engine. Figure 7 illustrates the approved coolant

ow connections. Proper cooling is important in minimizing

discharge air temperatures – see the tabulated technical

data on page 13 of this manual for specic requirements.

FIGURE 7 - BENDIX® 720CC TWIN CYLINDER COMPRESSOR PORT IDENTIFICATION

Discharge Port

Inlet

Port

Head

Bolt (8)

CYLINDER HEAD PORT IDENTIFICATION

The cylinder head connection ports are

identied with “cast in” numerals as follows:

AIR IN . . . . . . . . . . . . . 0

Compressed AIR OUT . . . . . 2

Coolant IN . . . . . . . . . . . 9

Coolant OUT. . . . . . . . . . 9

Safety

Valve Port

Coolant Port

(In or Out)

Coolant Port

(In or Out)

Oil

Supply

LUBRICATION INSPECTION

The compressor utilizes an internal oil feed design. Check

the exterior of the compressor (e.g. around the mounting

face) for the presence of oil seepage, and refer to the

troubleshooting section for appropriate tests and corrective

action. Refer to the tabulated technical data in the back of

this manual for oil pressure minimum values.

OIL PASSING INSPECTION

All reciprocating compressors pass a minimal amount of

oil. Air dyers will remove the majority of oil before it can

enter the air brake system. For particularly oil sensitive

systems, the Bendix® PuraGuard® system can be used in

conjunction with a Bendix® air dryer.

If compressor oil passing is suspected, refer to the

troubleshooting section (starting on page A-1) for the

symptoms and corrective action to be taken. In addition,

Bendix has developed the “Bendix® Air System Inspection

Cup” — or Bendix® BASIC™ kit — to help substantiate

suspected excessive oil passing. The steps to be followed

when using the BASIC kit are presented in APPENDIX B.

COMPRESSOR DRIVE INSPECTION

Check for noisy compressor operation, which could indicate

excessive drive component wear. Adjust and/or replace

as necessary. Check all compressor mounting bolts and

retighten evenly if necessary. Check for leakage. Repair

or replace parts as necessary.

CHARGING SYSTEM UNLOADING & GOVERNOR

TEST

Note: The Bendix 720cc DLU-style twin cylinder

compressor does not contain components to unload

the compressor. Therefore, the compressor pumps

continuously. In most systems that utilize an air dryer, the

governor and DLU-style air dryer are used to unload the

system (e.g. air is not being delivered to the brake system

reservoirs). When system unloading occurs, air from the

compressor will typically ow out the exhaust port of the

air dryer. Refer to Figure 6.

Test and inspect the unloading system (e.g. air dryer and

governor) for proper operation and pressure settings.

1. Make certain the unloader system lines (illustrated in

Figure 6) are connected and leak free.

2. Cycle the charging system between the loaded and

unloaded mode several times. This can be achieved by

applying the brakes to bleed down the system pressure.

Make certain that the governor cuts-in (charging

system resumes compressing air) at a minimum of

105 psi. Governor cut-out (charging system stops

delivering air to the brake system reservoirs) should be

approximately 15 - 20 psi greater than cut-in pressure.

Adjust or replace the governor as required.

AIR INDUCTION

The Bendix® 720cc twin cylinder compressor is only

permitted to be naturally aspirated – use of an engine

turbocharger as an air source is not allowed.

PREVENTIVE MAINTENANCE

Regularly scheduled maintenance is the single most

important factor in maintaining the air brake charging

system. Refer to Table A: Maintenance Schedule and

Usage Guidelines in the troubleshooting section (page

A-3) for a guide to various considerations that must be

given to maintenance of the compressor and other related

charging system components.

Important Note: Review the Bendix Warranty Policy

before performing any intrusive maintenance procedures.

An extended warranty may be voided if intrusive

maintenance is performed during this period.

EVERY 6 MONTHS, 1800 OPERATING HOURS,

OR AFTER EACH 50,000 MILES — WHICHEVER

OCCURS FIRST — PERFORM THE FOLLOWING

INSPECTIONS AND TESTS.

AIR INDUCTION INSPECTION

A supply of clean air is one of the single most important

factors in compressor preventive maintenance. Since

the air supply for the 720cc twin cylinder compressor and

engine is the engine air cleaner, periodic maintenance of

the engine air lter is necessary.

Inspect the compressor air induction system each time

engine air cleaner maintenance is performed.

1. Inspect the intake hose adapters for physical damage.

Make certain to check the adapters at both ends of the

intake hose or tubing.

2. Inspect the intake hose clamps and tighten them if

needed.

3. Inspect the intake hose or line for signs of drying,

cracking, chang and ruptures and replace if necessary.

4. Inspect the compressor’s cast inlet tube for physical

damage.

COMPRESSOR COOLING INSPECTION

Inspect the compressor discharge port, inlet cavity and

discharge line for evidence of restrictions and carbon

buildup. If more than 1/16" of carbon is found, thoroughly

clean or replace the affected parts. In some case, carbon

buildup indicates inadequate cooling. Closely inspect the

compressor cooling system. Check all compressor coolant

lines for kinks and restrictions to ow. Minimum coolant line

size is 3/8" Inside Diameter (I.D.) Check coolant lines for

internal clogging from rust scale. If coolant lines appear

suspicious, check the coolant ow and compare to the

tabulated technical data present in the back of this manual.

3. Note that the charging system cycles to the loaded and

unloaded conditions promptly. If prompt action is not

noted, repair or replace the governor and/or repair the

air dryer purge valve assembly.

IMPORTANT NOTE

Replacement air governors must have a minimum cut-in

pressure of 100 psi. The cut-in pressure is the lowest system

pressure registered in the gauges before the compressor

resumes compressing air.

SERVICE TESTS

GENERAL

The compressor operating and leakage tests listed below

need not be performed on a regular basis. These tests

should be performed when it is suspected that leakage is

substantially affecting compressor build-up performance, or

when it is suspected that the charging system is “cycling”

between the loaded (pumping) and unloaded (charging

system stops delivering air to the brake system reservoirs)

modes due to unloader system leakage.

IN SERVICE OPERATING TESTS

Compressor Performance: Build-up Test

This test is performed with the vehicle parked and the

engine operating at maximum recommended governed

speed. Fully charge the air system to governor cut-out (air

dryer purges). Pump the service brake pedal to lower the

system air pressure below 80 psi using the dash gauges.

As the air pressure builds back up, measure the time from

when the dash gauge passes 85 psi to the time it passes

100 psi. The time should not exceed 40 seconds. If the

vehicle exceeds 40 seconds, test for (and x) any air leaks

and then re-test the compressor performance. If the vehicle

does not pass the test the second time, use the Advanced

Troubleshooting Guide for Air Brake Compressors, starting

on page A-1 of this document, to assist your investigation

of the cause(s).

Note: All new vehicles are certied using the FMVSS

121 test (paragraph S5.1.1) by the vehicle manufacturer,

however the above test is a useful guide for in-service

vehicles.

Optional Comparative Performance Check

It may be useful to also conduct the above test with the

engine running at high idle (instead of maximum governed

speed), and record the time required to raise the system

pressure a selected range (for example: from 90 to 120 psi,

or from 100 to 120 psi, etc.) in the vehicle’s maintenance

les. Subsequent build-up times throughout the vehicle’s

service life can then be compared to the rst one recorded.

(Note: the 40 second guide in the test above does not

apply to this build-up time.) If the performance degrades

signicantly over time, use the Advanced Troubleshooting

Guide for Air Brake Compressors, starting on page A-1 of

this document, to assist investigation of the cause(s).

Note: When comparing build-up times, be sure to make

an allowance for any air system modications which would

cause longer times, such as adding air components or

reservoirs. Always check for air system leakage.

LEAKAGE TESTS

See the standard Air Brake System and Accessory Leakage

test on Page A-14, Test 2.

Note: Leakage in the air supply system (components

before the supply reservoir - such as the governor, air dryer,

reservoir drain cocks, safety valve, and check valves) will

not be registered on the vehicle dash gauges and must

be tested separately. Refer to the various maintenance

manuals for individual component leakage tests and the

Bendix “Test and Checklist” published in the Bendix Air

Brake System Handbook (BW5057) and on the back of

the Bendix Dual Circuit Brake System Troubleshooting

Card (BW1396).

CYLINDER HEAD

Check the cylinder head gaskets for air leakage.

1. With the engine running, lower the air system pressure

to 60 psi and apply a soap solution around the cylinder

head. Check the gaskets between the cylinder head

and the valve plate assembly, as well as the inlet reed

valve/gasket between the valve plate assembly and

crankcase for air leakage.

2. No leakage is permitted. If leakage is detected, replace

the compressor or repair the cylinder head using the

maintenance kit available from an authorized Bendix

parts outlet.

INLET & DISCHARGE VALVES

In order to test the inlet and discharge valves, it is necessary

to have shop air pressure and an assortment of ttings. A

soap solution is also required.

1. With the engine shut off, drain ALL air pressure from the

vehicle.

2. Disconnect the inlet and discharge lines.

3. Apply 120-130 psi shop air pressure to the discharge port

and then apply and release air pressure to the inlet port.

Soap the inlet port and note that leakage at the inlet port

does not exceed 200 sccm.

If excessive leakage is noted in Test 3, replace or repair

the compressor using genuine Bendix® replacements or

maintenance kits available from any authorized Bendix parts

outlet.

While it is possible to test for inlet and discharge leakage, it

may not be practical to do so. Inlet and discharge valve leakage

can generally be detected by longer compressor build-up and

recovery times. Compare current compressor build-up times

with the last several recorded times. Make certain to test for

air system leakage, as described under “In-Service Operating

Tests”, before making a determination that performance has

been lost.

COMPRESSOR REMOVAL & DISASSEMBLY

GENERAL

The following disassembly and assembly procedure is

presented for reference purposes and pre-supposes that

a rebuild or repair of the compressor is being undertaken.

Several maintenance kits are available and the instructions

provided with these parts and kits should be followed in lieu

of the instructions presented here.

MAINTENANCE KITS & SERVICE PARTS

BENDIX® 720CC TWIN CYLINDER COMPRESSOR

Compressor Seal Kit (Major) . . . . . . . . . . .K026808

Compressor Seal Kit (Minor) . . . . . . . . . . .K051352

Discharge Safety Valve Kit . . . . . . . . . . . .K026809

Compressor to Engine Supplied by the

Mounting Face Sealant . . . . . . . engine manufacturer

REMOVAL

In many instances it may not be necessary to remove the

compressor from the vehicle when installing the various

maintenance kits and service parts. The maintenance

technician must assess the installation and determine the

correct course of action. These instructions are general

and are intended to be a guide. In some cases additional

preparations and precautions are necessary. In all cases follow

the instructions contained in the vehicle maintenance

manual in lieu of the instructions, precautions and

procedures presented in this manual.

1. Block the wheels of the vehicle and drain the air

pressure from all the reservoirs in the system.

2. Drain the engine cooling system and the cylinder

head of the compressor. Identify and disconnect all

air, water and oil lines leading to the compressor.

3. Remove as much road dirt and grease from the

exterior of the compressor as possible.

4. Remove the discharge tting, if applicable, and note

their position on the compressor to aid in reassembly.

5. Remove any supporting bracketing attached to

the compressor and note their positions on the

compressor to aid in reassembly.

6. Remove the six mounting bolts that retain the

compressor to the side of the engine block. Note

the position of the six mounting bolts. Two of the six

bolts are shorter and must be installed in their original

locations. Remove the compressor from the vehicle.

7. Inspect drive gear and associated drive parts for

visible wear or damage. If the compressor drive

gear is worn or damaged, the compressor must be

replaced. Refer to the engine manufacturer's service

manual to address the associated engine drive parts.

8. If the compressor is being replaced, stop here and

proceed to “Installing the Compressor” at the end

of the assembly procedure. (Note: Replacement

compressors come with the drive gear pre-

assembled on the compressor.)

PREPARATION FOR DISASSEMBLY

Place a clean rag over the openings that expose the

gear and crankshaft / connecting rod assembly. Refer

to Figure 3. No contamination is permitted in these

areas.

Remove the balance of road dirt and grease from the

exterior of the compressor with a cleaning solvent. If the

rear end cover is being removed from the compressor,

mark it, along with the two cap screws, in relation to

the crankcase. It is also recommended to mark the

relationship of the cylinder head, cooling plate, valve

plate assembly and crankcase.

A convenient method to indicate the above relationships

is to use a metal scribe to mark the parts with numbers or

lines. Do not use marking methods, such as chalk, that

can be wiped off or obliterated during rebuilding.

Prior to disassembly make certain that the appropriate

kits are available. Refer to Figure 8 during the entire

disassembly and assembly procedure. The serviceable

items are identied by "Item" numbers 1 through 11.

End Cover

Cooling

Plate

Crankcase

Alignment Pins

(x2) - one at

each end

Valve Plate

Assembly

Cylinder Head

Crankcase

Cap

Screws

(x2)

Crankcase

Side Cover

Crankcase Side

Cover Cap

Screws (x6)

Compressor

Drive Gear

FIGURE 8 – BENDIX® 720CC TWIN CYLINDER COMPRESSOR EXPLODED VIEW

Item Qty. Description

1 1 Sealing Ring

2 1 Bendix® ST-4™ Safety Valve

Safety Valve Kit Pc. No. K026809 consists of the

following:

Item Qty. Description

3 8 Cap Screws (long)

4 2 Cap Screws (short)

5 1 Head Gasket

6 1 Cooling Plate Gasket

7 1 Inlet Reed Valve/Gasket

8 2 Crankcase O-ring

9 1 Cover

10 1 End Cover O-ring

11 1 Side Cover Gasket

Compressor Seal Kit (Major) Pc. No. K026808

consists of the following:

Item Qty. Description

9 1 Cover

10 1 End Cover O-ring

Compressor Seal Kit (Minor) Pc. No. K051352

consists of the following:

These items are also referenced in the following procedures

and are denoted by the numbers in parenthesis.

CYLINDER HEAD, COOLING PLATE & VALVE

PLATE ASSEMBLY

1. Remove the sealing ring (2) and discharge safety valve

(1) from the compressor cylinder head.

2. Remove the two short hex head screws (4) and eight

long hex head screws (3) from the compressor cylinder

head.

3. Gently tap the cylinder head, cooling plate and valve

plate assembly with a soft mallet to break the gasket

seal between the valve plate assembly and the

crankcase. Lift the cylinder head — with cooling plate

and valve plate assembly — off the crankcase.

4. Remove the metal inlet reed valve gasket(7).

5. Remove the two crankcase o-rings (8) from the deck

(top) of the crankcase. The o-rings are located in

countersunk holes, one on each side of the cylinder

bores.

6. Gently tap the removed cylinder head, cooling plate

and valve plate assembly with a soft mallet to break

the gasket seals. Then separate the cylinder head from

the cooling plate and valve plate assembly and remove

and discard the two head gaskets (5) and (6).

CRANKCASE FRONT COVER

1. Remove the cover (9) from the front of the crankcase.

Use a sharp, at head screw driver or a scraper. Place

the edge under the lip along the outside diameter of

the cover. Pry the cover from the cast surface until the

cover can be removed. Refer to Figure 10.

CRANKCASE SIDE COVER

1. Remove the six cap screws that secure the crankcase

side cover to the crankcase.

2. Gently tap the crankcase side cover with a soft mallet

to break the gasket seal between the crankcase side

cover and the crankcase. Remove the crankcase side

cover and the gasket (11).

REAR END COVER

1. Note: There are two cap screws used to retain the

end cover to the crankcase. There a two longer cap

screws (not shown in Figure 9) that are used to retain

the auxiliary drive unit (e.g. hydraulic pump) via the end

cover and torqued into the crankcase. If the auxiliary

drive unit has already been removed, these two cap

screws are no longer present on the end cover. Refer

to Figure 8 to see location of the cap screws in the end

cover.

2. Remove the two end cover cap screws that secure the

rear end cover to the crankcase.

3. Remove the rear end cover from the crankcase.

Remove and discard the o-ring (10) from the end cover.

CLEANING OF PARTS

GENERAL

All parts should be cleaned in a good commercial grade of

solvent and dried prior to inspection.

CRANKCASE

1. Carefully remove all sealant gasket material adhering

to the machined face of the crankcase. See Figure

3. Make certain not to scratch or mar the mounting

surface. Note: Keep the crankcase opening covered

to prevent any of the sealant material from entering.

FIGURE 9 - REAR END COVER ATTACHMENT BOLTS

M10x1.5

Cap

Screws

(Larger)

M8x1.25

Cap

Screws

(Smaller)

FIGURE 10 - FRONT COVER

Repeat this process on the engine mounting face as

well. Follow the instructions contained in the vehicle

maintenance manual in lieu of the instructions and

procedures presented in this manual.

2. Carefully remove all gasket material adhering to the

deck (top) of the crankcase. Remove any carbon

deposits from the deck of the crankcase. Make certain

not to scratch or mar the gasket surfaces.

CYLINDER HEAD, COOLING PLATE & VALVE

PLATE ASSEMBLY

1. Carefully remove all gasket material adhering to the

cylinder head, cooling plate and valve plate assembly.

Make certain not to scratch or mar the gasket surfaces.

Pay particular attention to the gasket surfaces of the

cylinder head and cooling plate.

2. Remove carbon deposits from the discharge and inlet

cavities of the cylinder head, cooling plate and valve

plate assembly. They must be open and clear in the

components. Make certain not to damage the parts.

3. Remove rust and scale from the cooling cavities and

passages in the cylinder head, cooling plate and valve

plate assembly and use shop air to clear debris from

the passages.

4. Check the threads in all cylinder head ports for galling

(e.g. abrasion, chang). Minor thread chasing (damage)

is permitted.

INSPECTION OF PARTS

CYLINDER HEAD, COOLING PLATE AND VALVE

PLATE ASSEMBLY

1. Carefully inspect the head gasket surfaces on the

cylinder head for deep gouges and nicks. Also, inspect

the cylinder head for any cracks or port thread damage.

If detected, the compressor must be replaced. If large

amounts of carbon build-up are present in the discharge

cavity, such that it restricts the air ow through the

cylinder head, the compressor should be replaced.

2. Carefully inspect both sides of the gasket surfaces

on the cooling plate for deep gouges and nicks.

Also, inspect the cooling plate for any cracks or other

damage. If damage is found, the compressor must be

replaced.

3. Carefully inspect the valve plate assembly gasket

surfaces (both sides) for deep gouges and nicks. Pay

particular attention to the gasket surface. An inlet

reed valve gasket (7) is used between the valve plate

assembly and crankcase. These gasket surfaces

must be smooth and free of all but the most minor

scratches. If excessive marring or gouging is detected,

the compressor must be replaced. If large amounts of

carbon build-up are present on the two main surfaces, in

the two discharge valve holes or between the discharge

valve and the discharge seat, the compressor should

be replaced.

REAR END COVER

Check for cracks and external damage. Check the

crankshaft rear bearing diameter in the rear end cover for

excessive wear, at spots or galling. Check the hydraulic

pump attachment pilot and threaded holes for damage.

Minor thread chasing is permitted, but do not re-cut the

threads. If any of these conditions are found, replace the

compressor.

CRANKCASE

Check the cylinder head gasket surface on the deck (top)

of the crankcase for nicks, gouges, and marring. A metal

gasket is used to seal the cylinder head to the crankcase.

This surface must be smooth and free of all but the most

minor scratching. If excessive marring or gouging is

detected, the compressor must be replaced.

Check the condition of the two countersunk holes on the

deck of the crankcase that retain the o-rings (8) and prevent

coolant leakage between the valve plate assembly and the

crankcase. The surface in contact with the o-ring should be

smooth and free of any scratches and gouges that could

cause leakage around the o-rings.

ASSEMBLY

General Note: All torques specied in this manual are

assembly torques and typically can be expected to fall off

after assembly is accomplished. Do not re-torque after

initial assembly torques fall unless instructed otherwise.

A compiled listing of torque specications is presented on

page 13.

INCH POUNDS TO FOOT POUNDS

To convert inch pounds (in-lbs) to foot pounds (ft-lbs) of

torque, divide inch-pounds by 12.

Example: 12 in-lbs = 1 ft-lbs

FOOT POUNDS TO INCH POUNDS

To convert foot pounds to inch pounds of torque, multiply

foot pounds by 12.

Example: 1 ft-lbs x 12 = 12 in-lbs

CRANKCASE FRONT COVER

1. Position the new cover (9) over the hole in the front

of the crankcase. Using a rubber mallet, drive the

cover into the hole in the front of the crankcase until

the outside diameter of the cover is ush with the cast

surface.

CRANKCASE SIDE COVER

1. Position the gasket (11) on the crankcase side cover.

Install the crankcase side cover on the side of the

crankcase using the six (6) cap screws previously

removed. “Snug” all six cap screws then torque to

97–115 in-lbs (11–13 Nm). When torquing the bolts, it is

best to start with the two mid bolts then use a crossing

pattern with the four remaining bolts.

REAR END COVER

1. Install the o-ring (10) on the rear end cover.

2. Orient the rear end cover to the crankcase using the

reference marks made during disassembly. Carefully

install the rear end cover in the crankcase. Make certain

not to damage the crankshaft bearing surface.

3. Install the two end cover cap screws. Refer to Figure

9 to ensure that the two cap screws are installed in

the proper crankcase bolt holes. “Snug” the screws,

then tighten to between 195 and 212 in-lbs (22-24

Nm).

CYLINDER HEAD, COOLING PLATE & VALVE

PLATE ASSEMBLY

1. Install the two crankcase o-rings (8) into the countersunk

holes on the deck of the crankcase.

2. Note the position of the two protruding crankcase

alignment pins on the deck (top) of the crankcase.

Install the metal inlet reed valve gasket (7) over the

alignment pins on the crankcase; being careful not to

disturb the crankcase o-rings (8).

3. Position the valve plate assembly on the crankcase

so that the alignment pins in the crankcase t into the

corresponding holes in the valve plate assembly.

4. Position the embossed metal head gasket (5) over

the alignment bushings protruding from the top of

the cooling plate. Position the embossed metal head

gasket (6) over the alignment bushings on the opposite

side of the cooling plate. When properly positioned, the

outline of the two embossed gaskets match the outline

of the cooling plate, and the machined sealing surfaces

on the cooling plate, will be covered by the embossed

metal gasket material. Important: The two gaskets are

different and must be installed on the proper side of the

cooling plate for the compressor to function properly.

See Figure 8 for proper head gasket positions.

5. Install the cooling plate with the pre-installed head

gaskets (5 and 6) onto the valve plate assembly.

Align the alignment bushings on the cooling plate over

the oversized countersunk holes of the valve plate

assembly. Again, when properly installed, the outline of

the cooling plate matches the outline of the valve plate

assembly.

6. Position and install the cylinder head over the alignment

bushings protruding from the cooling plate. When

properly installed, the outline of the cylinder head

assembly will match the outline of the cooling plate and

valve plate assembly.

Note: To assist with correct installation, the alignment

bushings in the cooling plate only t into two of the four

corner head bolt holes on the valve plate assembly and

the cylinder head.

7. Install the eight long hex head cap screws (3) into the

cylinder head. Note: A light lm of oil should be

applied to the threads of these cap screws prior to

installing. Oil should not be applied to any of the

other hardware.

8. Install the two short hex head cap screws (4) into the

cylinder head. Important: The two short hex head

cap screws (4) must be installed in hole positions

designated as sequence “3” and “8” in Figure 11.

9. To ensure the cylinder head cap screws are properly

torqued, the following three step procedure must be

adhered to. Each cap screw must be tightened a total

of three times. Referencing Figure 11, tighten each

screw—in numerical order—to the torque identied in

Step 1. Once all have been tightened follow the same

procedure for Steps 2 and 3.

10. Install the washer (1) and safety valve (2) in the side

(discharge) port identied by the number '2' on the

cylinder head (3) as shown in Figure 11, then tighten

to a torque not to exceed 66 foot pounds (90 Nm).

INSTALLING THE COMPRESSOR

1. Apply a liquid gasket sealant to the compressor /

engine mounting interface (Refer to Figure 3 for

compressor mounting face). Follow the “engine or

vehicle manufacturer's guidelines for the proper liquid

gasket sealant material and application procedure.

2. Secure the compressor on the engine mounting

interface using the six mounting bolts. NOTE: There

are two short bolts and four long bolts. Be sure to use

the proper length bolt for the crankcase bolt holes. Run

each of the bolts down nger tight, making sure not to

smear the liquid gasket material on the sealing surface.

Once the bolts are all nger tight, tighten the mounting

bolts per the engine manufacturer's recommended

torquing sequence and torque requirements.

3. Install any supporting brackets on the compressor in

the same position(s) noted and marked during removal.

4. Inspect all air and coolant lines and ttings before

reconnecting them to the compressor. Make certain

o-ring seals are in good or new condition, the threads

are clean, and the ttings are free of corrosion. Replace

as necessary.

5. Install the discharge and coolant ttings, if applicable, in

the same position on the compressor noted and marked

during disassembly. See the Torque Specications for

various tting sizes and types of thread at the rear of

this manual. Tighten all hose clamps.

6. Before returning the vehicle to service, perform

the Operation and Leakage Tests specied in this

manual. Pay particular attention to all lines and hoses

disconnected during the maintenance and check for air,

oil, and coolant leaks at compressor connections and

the compressor engine interface. Also check for noisy

operation.

BENDIX® 720CC TWIN CYLINDER

COMPRESSOR SPECIFICATIONS

Typical weight ....................................... 67 lbs. (30.5 kg.)

Number of cylinders ....................................................... 2

Bore Diameter .................................... 3.622 in. (92 mm)

Stroke ................................................. 2.126 in. (54 mm)

Calculated displacement at 1250 RPM ............ 31.6 CFM

Flow Capacity @ 1800 RPM & 120 psi .......... 30.3 CFM

Flow Capacity @ 3000 RPM & 120 psi ............ 45.3 CFM

Approximate horsepower required:

Loaded 1800 RPM at 120 psig ......................... 9.1 hp

Loaded 1800 RPM at 0 psig (DLU) ................. 4.4 hp

Minimum coolant ow

at maximum RPM ....................... 2.64 GPM (10 LPM)

Maximum coolant temperature ..................... 203°F (95°C)

Maximum inlet air temperature ................... 122°F (50°C)

Maximum system pressure .....................................150 psi

Minimum oil pressure required ............................... 10 psi

TORQUE SPECIFICATIONS

Assembly Torques

M8 x 1.25-6g Cylinder Head Bolts .. 221 in-lbs + 180° turn

(25 Nm + 180° turn)

M10 x 1.5 End Cover Bolts .........................195–213 in-lbs

(22 – 24 Nm)

M6 x 1 Crankcase Side Cover Bolts ............. 97–115 in-lbs

(11–13 Nm)

M26 x 1.5 Safety Valve .................................. 59–66 ft-lbs

(80–90 Nm)

M26 x 1.5 Discharge Port Fittings ........................ 66 ft-lbs

(90 Nm) Maximum

M16 x 1.5-6H Water Port Fittings ..................... 33.2 ft-lbs

(45 Nm) Maximum

FIGURE 11 - CYLINDER HEAD BOLT TORQUE SEQUENCE

Sequence - Numerical order 1 through 10

Step Torque (in-lbs) Torque (Nm)

1 177 20

2 221 25

3 221 + 180° turn 25 + 180° turn

2 6

4 5

Notes

A-1

Appendix A

Advanced Troubleshooting Guide for Air Brake Compressors

Air brake charging system:

Slow build (9.0) .....................................A-9-10

Doesn’t build air (10.0) ............................. A-11

Air dryer:

Doesn’t purge (14.0) ................................ A-12

Safety valve releases air (12.0) ............... A-12

Compressor:

Constantly cycles (15.0) .......................... A-12

Leaks air (16.0) ........................................ A-13

Safety valve releases air (11.0) ............... A-11

Noisy (18.0) ............................................ A-13

Reservoir:

Safety valve releases air (13.0) ............... A-12

INDEX

Air Coolant

Engine

Oil

Compressor leaks coolant (17.0)....................A-13

Oil consumption (6.0) ......................................A-9

Oil Test Card results (1.0) .................................A-4

Oil is present:

On the outside of the compressor (2.0) ......A-5

At the air dryer purge/exhaust

or surrounding area (3.0) ........................A-5

In the supply reservoir (4.0) .................... A-6-8

At the valves (5.0) .......................................A-8

At air dryer cartridge (7.0) ...........................A-9

In the ping tank or compressor

discharge aftercooler (8.0) ......................A-9

Symptom Page Number

(1) Oil Leakage at Head Gasket .....A-14

(2) System Leakage .......................A-14

(3) Compressor Discharge and

Air Dryer Inlet Temperature ...........A-15

(4) Governor Malfunction ................A-14

(5) Governor Control Line ...............A-15

(6) Compressor Unloader ...............A-15

BASIC™ Test Information ........ A-16-18

Test Procedures

Maintenance Schedule and

Usage Guidelines (Table A) ..... A-3

Symptom Page Number

Maintenance & Usage Guidelines

The guide consists of an introduction to air brake charging system components, a table

showing recommended vehicle maintenance schedules, and a troubleshooting symptom

and remedy section with tests to diagnose most charging system problems.

A-2

Introduction to the Air Brake Charging System

builds the air pressure for the air brake system. The air

compressor is typically cooled by the engine coolant system

and lubricated by the engine oil supply.

This Bendix® 720cc compressor is a “discharge line

unloader” (DLU-style) compressor, meaning that the

compressor pumps continuously, unlike some compressor

designs which use an “unloader” mechanism in the

compressor head to switch from a pumping mode to a

non-pumping mode. Instead, the control of air delivery to

the vehicle’s air system is managed by using a separate

discharge line unloader valve mounted in parallel with the

compressor, a turbo cut-off style of the air dryer, and a

governor (see gure below). The discharge line unloader

(DLU) valve and governor control the brake system

air pressure between a preset maximum and minimum

pressure level by monitoring the pressure in the service (or

“supply”) reservoir. When the air pressure becomes greater

than that of the preset “cut-out”, the governor controls the

discharge line unloader valve such that the air from the

compressor ows through the exhaust of the discharge

line unloader valve and to atmosphere (i.e. preventing air

delivery to the reservoirs) and also causes the air dryer to

purge. As the service reservoir air pressure drops to the

“cut-in” setting of the governor, the governor returns the

discharge line unloader valve back to building air mode

and the air dryer to air drying mode.

As the atmospheric air is compressed, all the water vapor

originally in the air is carried along into the air system, as

well as a small amount of the lubricating oil as vapor.

The duty cycle is the ratio of time the compressor

spends building air to the total engine running time. Air

compressors are designed to build air (run “loaded”) up to

25% of the time. Higher duty cycles cause conditions that

affect air brake charging system performance which may

require additional maintenance. Factors that add to the

duty cycle are: air suspension; additional air accessories;

use of an undersized compressor; frequent stops; and

excessive leakage from fittings, connections, lines,

chambers or valves, etc.

The discharge line allows the air, water-vapor and

oil-vapor mixture to cool between the compressor and air

dryer. The typical size of a vehicle's discharge line, (see

column 2 of Table A on page A-3) assumes a compressor

with a normal (less than 25%) duty cycle, operating in

a temperate climate. See Bendix and/or other air dryer

manufacturer guidelines as needed.

When the temperature of the compressed air that enters

the air dryer is within the normal range, the air dryer can

remove most of the charging system oil. If the temperature

of the compressed air is above the normal range, oil — as

oil-vapor — is able to pass through the air dryer and into the

air system. Larger diameter discharge lines, and/or longer

discharge line lengths, can help reduce the temperature.

The discharge line must maintain a constant slope down

from the compressor to the air dryer inlet tting to avoid low

points where ice may form and block the ow. If, instead,

ice blockages occur at the air dryer inlet, insulation may be

added here; or if the inlet tting is a typical 90 degree tting,

it may be changed to a straight — or 45 degree — tting.

For more information on how to help prevent discharge

line freeze-ups, see Bendix Bulletins TCH-008-021 and

TCH-008-022 (see pages A-19-21). Shorter discharge

line lengths or insulation may be required in cold climates.

The air dryer contains a lter that collects oil droplets, and

a desiccant bed that removes almost all of the remaining

water vapor. The compressed air is then passed to the air

brake service (supply) reservoir. The oil droplets and the

water collected are automatically purged when the governor

reaches its “cut-out” setting.

For vehicles with accessories that are sensitive to small

amounts of oil, we recommended installation of a Bendix®

PuraGuard® system lter, designed to minimize the amount

of oil present.

The Air Brake Charging System supplies the compressed air for the braking system as well

as other air accessories for the vehicle. The system usually consists of an air compressor, governor,

discharge line, air dryer, and service reservoir.

UNL

RES

21 22

UNL

Compressor

Governor

Air Dryer

Front Service

Reservoir

Rear Service

Reservoir

DLU Valve

A-3

Compressor with up to 25% duty cycle

Footnotes:

1. With increased air demand the air dryer cartridge needs to be replaced

more often.

2. Use the drain valves to slowly drain all reservoirs to zero psi.

3. Allow the oil/water mixture to fully settle before measuring oil quantity.

4. To counter above normal temperatures at the air dryer inlet, (and resultant

oil-vapor passing upstream in the air system) replace the discharge line

with one of a larger diameter and/or longer length. This helps reduce the

air's temperature. If sufcient cooling occurs, the oil-vapor condenses

and can be removed by the air dryer. Discharge line upgrades are not

covered under warranty. Note: To help prevent discharge line freeze-

ups, shorter discharge line lengths or insulation may be required in

cold climates. (See Bendix Bulletins TCH-008-021 and TCH-008-022,

included in Appendix B, for more information.)

Recom- Recom- Acceptable

Typical Discharge mended mended Reservoir

Compressors Line Air Dryer Reservoir Oil Contents3

Spec'd Cartridge Drain at Regular

Replacement1 Schedule2 Drain Intervals

High Air Use

Low Air Use

e.g. Double/triple trailer,

open highway coach, (most)

pick-up & delivery, yard or

terminal jockey, off-highway,

construction, loggers, concrete

mixer, dump truck, re truck.

e.g. Line haul single trailer

w/o air suspension, air over

hydraulic brakes.

e.g. Line haul single trailer

with air suspension, RV,

school bus.

less

Table A: Maintenance Schedule and Usage Guidelines

Recom-

mended

Every

Month -

Max of

every 90

days

Every

Month

Every 3

Years

Every 2

Years

Every

Year

I.D.

Vehicle Used for:

Column 1 Column 2 Column 3 Column 4 Column 5

Regularly scheduled maintenance is the single most important factor in maintaining the air brake charging system.

Length

6 ft.

1/2 in.

9 ft.1/2 in.

12 ft.

1/2 in.

3/4 in. 12 ft.

BASIC test

acceptable

range:

5 oil units

per month.

See

Appendix

For oil carry-over

control4 suggested

upgrades:

5/8 in. 15 ft.

For oil carry-over

control4 suggested

upgrades:

5/8 in. 9 ft.

For oil carry-over

control4 suggested

upgrades:

5/8 in. 12 ft.

Compressor with less than 15% duty

cycle

Compressor with up to 25% duty cycle

Bendix®

BASIC™ test

acceptable

range:

3 oil units

per month.

See

Appendix

For the

BASIC™

Test Kit:

Order

Bendix

P/N

5013711

e.g. City transit bus, refuse,

bulk unloaders, low boys,

urban region coach, central

tire ination.

Note: Compressor and/or air dryer upgrades are recommended

in cases where duty cycle is greater than the normal range

(for the examples above).

For correct compressor upgrades consult Bendix.

* See Appendix E for the Application Matrix for Bendix®

360cc and 720cc air compressors.

No. of

Axles

See Appendix

E for Engine

Application

Matrix for

Bendix®

360cc Single

Cylinder and

720cc Two

Cylinder

Compressors

for

International

Maxxforce®

Big Bore

Engines

A-4

Air Brake Charging System Troubleshooting

1.0 Oil Test Card

Results

Not a valid test. Discontinue using this test.

Do not use this card test to diagnose compressor

"oil passing" issues. They are subjective

and error prone. Use only the Bendix® Air

System Inspection Cup (BASIC™) test and the

methods described in this guide for advanced

troubleshooting.

The Bendix® BASIC™ test is the denitive

method for judging excessive oil fouling/

oil passing. (See Appendix B, on page A-16

for a owchart and expanded explanation of

the checklist used when conducting the BASIC

test.)

Symptom: What it may indicate: What you should do:

How to use this guide:

Find the symptom(s) that you see, then move to the right

to nd the possible causes (“What it may indicate”) and

remedies (“What you should do”).

Review the warranty policy before performing any intrusive

compressor maintenance. Unloader or cylinder head gasket

replacement and resealing of the bottom cover plate are

usually permitted under warranty. Follow all standard safety

procedures when performing any maintenance.

Look for:

Normal - Charging system is working within

normal range.

Check - Charging system needs further

investigation.

Bendix®

BASIC™ Test





GENERAL SAFETY GUIDELINES

WARNING! PLEASE READ AND FOLLOW THESE INSTRUCTIONS

TO AVOID PERSONAL INJURY OR DEATH:

When working on or around a vehicle, the following guidelines should be observed AT ALL TIMES:

▲ Park the vehicle on a level surface, apply the

parking brakes and always block the wheels.

Always wear personal protection equipment.

▲Stop the engine and remove the ignition key

when working under or around the vehicle.

When working in the engine compartment,

the engine should be shut off and the ignition

key should be removed. Where circumstances

require that the engine be in operation, EXTREME

CAUTION should be used to prevent personal

injury resulting from contact with moving,

rotating, leaking, heated or electrically-charged

components.

▲Do not attempt to install, remove, disassemble

or assemble a component until you have read,

and thoroughly understand, the recommended

procedures. Use only the proper tools and

observe all precautions pertaining to use of those

tools.

▲If the work is being performed on the vehicle’s

air brake system, or any auxiliary pressurized air

systems, make certain to drain the air pressure

from all reservoirs before beginning ANY work

on the vehicle. If the vehicle is equipped with a

Bendix® AD-IS® air dryer system, a Bendix® DRM™

dryer reservoir module, or a Bendix® AD-9si™ air

dryer, be sure to drain the purge reservoir.

▲ Following the vehicle manufacturer’s

recommended procedures, deactivate the

electrical system in a manner that safely removes

all electrical power from the vehicle.

▲Never exceed manufacturer’s recommended

pressures.

▲Never connect or disconnect a hose or line

containing pressure; it may whip. Never remove

a component or plug unless you are certain all

system pressure has been depleted.

▲ Use only genuine Bendix® brand replacement

parts, components and kits. Replacement

hardware, tubing, hose,  ttings, etc. must be of

equivalent size, type and strength as original

equipment and be designed speci cally for such

applications and systems.

▲Components with stripped threads or damaged

parts should be replaced rather than repaired.

Do not attempt repairs requiring machining or

welding unless speci cally stated and approved

by the vehicle and component manufacturer.

▲Prior to returning the vehicle to service, make

certain all components and systems are restored

to their proper operating condition.

▲ For vehicles with Automatic Traction Control

(ATC), the ATC function must be disabled (ATC

indicator lamp should be ON) prior to performing

any vehicle maintenance where one or more

wheels on a drive axle are lifted off the ground

and moving.

▲The power MUST be temporarily disconnected

from the radar sensor whenever any tests USING

A DYNAMOMETER are conducted on a Bendix®

Wingman® Advanced™-equipped vehicle.

▲ You should consult the vehicle manufacturer's operating and service manuals, and any related literature,

in conjunction with the Guidelines above.

A-5

Symptom: What it may indicate: What you should do:

2.2 Oil leaking

from compressor:

(a) Excessive leak at head gasket.

(b)Leak at bottom cover plate.

(c)Leak at internal rear flange

gasket.

(d)Leak through crankcase.

(e) (If unable to tell source of leak.)

Go to Test 1 on page A-14.

Reseal bottom cover plate using RTV

silicone sealant.

Replace compressor.

Clean compressor and check periodically.

Air brake charging system functioning

normally.

Air dryers remove water and oil from the air

brake charging system.

Check that regular maintenance is being

performed. Return the vehicle to service.

An optional kit (Bendix piece number

5011327 for the Bendix® AD-IS® or AD-IP®

air dryers, or 5003838 for the Bendix® AD-9®

air dryer) is available to redirect the air dryer

exhaust.

3.0 Oil at air dryer

purge/exhaust or

surrounding area

2.0 Oil on the

Outside of the

Compressor

Find the source and repair. Return the vehicle

to service.

Repair or replace as necessary. If the

mounting bolt torques are low, replace the

gasket.

Replace the tting gasket. Inspect inlet

hose and replace as necessary.

Replace gasket or tting as necessary to

ensure good seal.

Inspect and repair as necessary.

Engine and/or other accessories

leaking onto compressor.

(a)Leak at the front or rear (fuel

pump, etc.) mounting ange.

(b) Leak at air inlet tting.

(d) Loose/broken oil line ttings.

2.1 Oil leaking at

compressor / engine

connections:

Head

gaskets and

rear ange

gasket

locations.



(a)

(c)

A-6

Symptom: What it may indicate: What you should do:

4.0 Oil in Supply or

Service Reservoir

(air dryer installed)

(If a maintained Bendix®

PuraGuard® system

lter or Bendix®

PuraGuard® QC oil

coalescing

lter is installed, call

1-800-AIR-BRAKE

(1-800-247-2725, option

2) and speak to a Tech

Team member.)

(a) If air brake charging system

maintenance has not been

performed. That is, reservoir(s)

have not been drained per the

schedule in Table A on page

A-3, Column 4 and/or the air

dryer maintenance has not been

performed as in Column 3.

(b) If the vehicle maintenance has

been performed as recommended

in Table A on page A-3, some oil in

the reservoirs is normal.

Drain all air tanks and check vehicle at next

service interval using the Bendix BASIC

test. See Table A on page A-3, column 3

and 4, for recommended service schedule.

Drain all air tanks into Bendix BASIC test

cup (Bendix Air System Inspection Cup).

If less than one unit of reservoir contents

is found, the vehicle can be returned to

service. Note: If more than one oil unit

of water (or a cloudy emulsion mixture)

is present, change the vehicle's air dryer,

check for air system leakage (Test 2, on

page A-14), stop inspection and check

again at the next service interval.

See the BASIC test kit for full details.

If less than one "oil unit" of water (or water/

cloudy emulsion mixture) is present, use the

BASIC cup chart on the label of the cup to

determine if the amount of oil found is within

the acceptable level.

If within the normal range, return the

vehicle to service. For vehicles with

accessories that are sensitive to small

amounts of oil, consider a Bendix®

PuraGuard® QC oil coalescing lter.

If outside the normal range go to Symptom

4.0(c).

Also see the Table A on page A-3, column

3 for recommended air dryer cartridge

replacement schedule.

Maintenance

Go to Test 2 on page A-14.

See Table A, column 1, on page A-3 for

recommended compressor sizes.

 If the compressor is "too small" for

the vehicle's role (for example, where a

vehicle's use has changed or service condi-

tions exceed the original vehicle or engine

OE spec's) then upgrade the compressor.

Note: The costs incurred (e.g. installing

a larger capacity compressor, etc.) are

not covered under original compressor

warranty.

 If the compressor is correct for the

vehicle, go to Symptom 4.0 (e).

Duty cycle too high

See Table A, on page

A-3, for maintenance

schedule information.

Drain all air tanks (reservoirs)

into the Bendix® BASIC™ test

cup. (Bendix kit P/N 5013711).

The duty cycle is the ratio of time the compressor spends

building air to total engine running time. Air compressors

are designed to build air (to "run loaded") up to 25% of the

time. Higher duty cycles cause conditions that affect air

brake charging system performance which may require

additional maintenance. Factors that add to the duty cycle

are: air suspension, additional air accessories, use of an

undersized compressor, frequent stops, excessive leakage

from ttings, connections, lines, chambers or valves, etc.

(d) Compressor may be undersized for

the application.

(a)

A-7

Symptom: What it may indicate: What you should do:

(e) Air compressor discharge and/or

air dryer inlet temperature too

high.

(f) Insufcient coolant ow.

(g) Restricted discharge line.

Check temperature as outlined in Test 3 on

page A-14. If temperatures are normal go

to 4.0(h).

Inspect coolant line. Replace as necessary.

Inside Diameter (I.D.) is 1/2".

Inspect the coolant lines for kinks and

restrictions and ttings for restrictions.

Replace as necessary.

Verify coolant lines go from engine block to

compressor and back to the water pump.

Repair as necessary.

If discharge line is restricted or more than

1/16" carbon build-up is found, replace the

discharge line. See Table A, column 2, on

page A-3 for recommended size. Replace

as necessary.

The discharge line must maintain a

constant slope down from the compressor

to the air dryer inlet tting to avoid low points

where ice may form and block the ow.

If, instead, ice blockages occur at the air

dryer inlet, insulation may be added here,

or if the inlet tting is a typical 90 degree

tting, it may be changed to a straight or

45 degree tting. For more information on

how to help prevent discharge line freeze-

ups, see Bendix Bulletins TCH-008-021

and TCH-008-022 (Appendix B). Shorter

discharge line lengths or insulation may be

required in cold climates.

Temperature

Other

Check compressor air inlet line for restric-

tions, brittleness, soft or sagging hose

conditions etc. Repair as necessary. Inlet

line size is 3/4 ID. Maximum restriction

requirement for compressors is 25 inches

of water.

Check the engine air lter and service if

necessary (if possible, check the air lter

usage indicator).

(h) Restricted air inlet (not enough air

to compressor).

(g)

4.0 Oil in Supply

or Service

Reservoir*

(air dryer installed)

(continued)

Kinked discharge line shown.

Partly

collapsed

inlet line

shown.

Testing the temperature

at the discharge tting. Inspecting the coolant hoses.

*If a maintained Bendix® PuraGuard® system lter or Bendix® PuraGuard® QC oil coalescing

lter is installed, call 1-800-AIR-BRAKE (1-800-247-2725, option 2) and speak to a Tech Team

member.

(g)

(e) (f)

(h)

A-8

Symptom: What it may indicate: What you should do:

(i) Poorly filtered inlet air (poor air

quality to compressor).

(j) Governor malfunction or setting.

(k) Compressor malfunction.

4.0 Oil in Supply

or Service

Reservoir*

(air dryer installed)

(continued)

Check for leaking, damaged or defective

compressor air inlet components (e.g.

induction line, ttings, gaskets, lter bodies,

etc.). Repair inlet components as needed.

Note: Dirt ingestion will damage compressor

and is not covered under warranty.

Go to Test 4 on page A-15.

If you found excessive oil present in the

service reservoir in step 4.0 (b) above and

you did not nd any issues in steps 4.0 (c)

through 4.0 (j) above, the compressor may

be passing oil.

Replace compressor. If still under warranty,

follow normal warranty process. Note: After

replacing a compressor, residual oil may

take a considerable period of time to be

ushed from the air brake system.

Other (cont.)

Inspect the

engine air

cleaner.

** SAE J2024 outlines the tests all air brake system

pneumatic components need to be able to pass,

including minimum levels of tolerance to contamination.

5.0 Oil present

at valves (e.g. at

exhaust, or seen

during servicing).

Air brake system valves are required

to tolerate a light coating of oil.

A small amount of oil does not affect SAE

J2024** compliant valves.

Check that regular maintenance is being

performed and that the amount of oil in the

air tanks (reservoirs) is within the accept-

able range shown on the Bendix® BASIC™

test cup (see also column 5 of Table A on

page A-3). Return the vehicle to service.

For oil-sensitive systems, see page A-16.

Genuine

Bendix®

valves are

all SAE

J2024

compliant.

*If a maintained Bendix® PuraGuard® system lter or Bendix® PuraGuard® QC oil coalescing

lter is installed, call 1-800-AIR-BRAKE (1-800-247-2725, option 2) and speak to a Tech Team

member.

Crankcase Flooding

Consider installing a compressor bottom drain kit

(where available) in cases of chronic oil passing where

all other operating conditions have been investigated.

Bendix compressors are designed to have a 'dry'

sump and the presence of excess oil in the crankcase

can lead to oil carryover.

A-9

Symptom: What it may indicate: What you should do:

8.0 Oil in ping tank

or compressor

discharge

aftercooler.

Air brake charging system is functioning

normally.

Air dryers remove water and oil from

the air brake charging system. A small

amount of oil is normal. Check that regular

maintenance is being performed and that

the amount of oil in the air tanks (reservoirs)

is within the acceptable range shown by the

Bendix® BASIC™ test (see also column 5

of Table A on page A-3). Replace the air

dryer cartridge as needed and return the

vehicle to service.

7.0 Oil present

at air dryer

cartridge during

maintenance.

A problem with engine or other engine

accessory.

See engine service manual.

6.0 Excessive oil

consumption in

engine.

Air brake charging system is functioning

normally.

Follow vehicle OE maintenance

recommendation for these components.

(a) Air brake charging system

functioning normally.

(b) Air brake system leakage.

the application.

(d) Compressor unloader mechanism

malfunction.

(e) Damaged compressor head

gasket.

Using dash gauges, verify that the

compressor builds air system pressure

from 85–100 psi in 40 seconds or less with

engine at full governed rpm. Return the

vehicle to service.

Go to Test 2 on page A-14.

See Table A, column 1, on page A-3 for

some typical compressor applications. If the

compressor is "too small" for the vehicle's

role, for example, where a vehicle's use has

changed, then upgrade the compressor.

Note: The costs incurred (e.g. installing

a larger capacity compressor, etc.) are

not covered under original compressor

warranty.

Go to Test 6 on page A-15.

An air leak at the head gasket may indi-

cate a downstream restriction such as a

freeze-up or carbon blockage and/or could

indicate a defective or missing safety valve.

Find blockage (go to 9.0(f) for details) and

then replace the compressor. Do not re-

use the safety valve without testing. See

Symptom 12.0(a).

9.0 Air brake

charging system

seems slow to

build pressure.

The engine

service

manual

has more

information.

Oil shown

leaking

from an

air dryer

cartridge.

(d) is not applicable for the

compressor featured in this SD

sheet —- information is shown

for reference only.

A-10

Symptom: What it may indicate: What you should do:

(g) Restricted air inlet (not enough air

to compressor).

Check compressor air inlet line for restric-

tions, brittleness, soft or sagging hose con-

ditions etc. Repair as necessary. Refer to

vehicle manufacturer’s guidelines for inlet

line size.

Check the engine air lter and service if

necessary (if possible, check the air lter

usage indicator).

(i) Compressor malfunction. Replace the compressor only after making

certain that none of the preceding conditions,

9.0 (a) through 9.0 (h), exist.

(h) Poorly filtered inlet air (poor air

quality to compressor).

Check for leaking, damaged or defective

compressor air inlet components (e.g.

induction line, ttings, gaskets, lter bodies,

etc.). Repair inlet components as needed.

Note: Dirt ingestion will damage compressor

and is not covered under warranty.

9.0 Air brake

charging system

seems slow to

build pressure.

(continued)

(f) Restricted discharge line. If the discharge line is restricted:

 By more than 1/16" carbon build-up,

replace the discharge line (see Table A,

column 2, on page A-3 for recommended

size) and go to Test 3 on page A-14.

 By other restrictions (e.g. kinks).

Replace the discharge line. See Table A,

column 2, on page A-3 for recommended

size. Re-test for air build. Return vehicle to

service or, if problem persists, go to 9.0(a).

The discharge line must maintain a

constant slope down from the compressor

to the air dryer inlet tting to avoid low points

where ice may form and block the ow.

If, instead, ice blockages occur at the air

dryer inlet, insulation may be added here,

or if the inlet tting is a typical 90 degree

tting, it may be changed to a straight or

45 degree tting. For more information on

how to help prevent discharge line freeze-

ups, see Bendix Bulletins TCH-008-021

and TCH-008-022 (Appendix B). Shorter

discharge line lengths or insulation may be

required in cold climates.

Kinked discharge line shown.

Dash gauges.

Partly collapsed

inlet line shown.

(f)

(g)

Engine Oil Quality

Inadequate oil change intervals, the formulation of the

oil and/or the quality of oil lter used can all lead to poor

oil quality. These can increase the rate at which carbon

builds up in the discharge line. Bendix recommends oil

soot (solids) be maintained at less than 3%.

A-11

Symptom: What it may indicate: What you should do:

10.0 Air charging

system doesn’t

build air.

(a) Governor malfunction*.

(b) Restricted discharge line.

exhaust port frozen open.

(d) Compressor malfunction.

Go to Test 4 on page A-15.

See 9.0(f).

Replace air dryer heater.

Replace the compressor only after making

certain the preceding conditions do not

exist.

11.0 Compressor

safety valve

releases air

(Compressor

builds too much

air).

(a) Restricted discharge line. If the discharge line is restricted:

 By more than 1/16" carbon build-up,

replace the discharge line (see Table A,

column 2, on page A-3 for recommended

size) and go to Test 3 on page A-14.

 By other restrictions (e.g. kinks).

Replace the discharge line. See Table A,

column 2, on page A-3 for recommended

size.

The discharge line must maintain a

constant slope down from the compressor

to the air dryer inlet tting to avoid low points

where ice may form and block the ow.

If, instead, ice blockages occur at the air

dryer inlet, insulation may be added here,

or if the inlet tting is a typical 90 degree

tting, it may be changed to a straight or

45 degree tting. For more information on

how to help prevent discharge line freeze-

ups, see Bendix Bulletins TCH-008-021

and TCH-008-022 (Appendix B). Shorter

discharge line lengths or insulation may be

required in cold climates.

Inspect air lines and verify check valves are

operating properly.

Ensure discharge line is installed into the

inlet of the air dryer and delivery is routed

to the service reservoir.

Verify relief pressure is 250 psi. Replace if

defective.

Go to Test 6 on page A-15.

Go to Test 4 on page A-15.

Damaged

discharge

line shown.

* Note: For the Bendix® DuraFlo 596™ air compressor, not only

the governor, but also the SV-1™ synchro valve used would

need to be tested. See Bulletin TCH-001-048.



(b) Downstream air brake system check

valves or lines may be blocked or

damaged.

(d) Compressor safety valve

malfunction.

(e) Compressor unloader mechanism

malfunction.

(f) Governor malfunction.

A-12

Symptom: What it may indicate: What you should do:

15.0 Compressor

constantly cycles

(compressor

remains unloaded

for a very short

time.)

(a) Air brake charging system

maintenance not performed.

(b) Compressor unloader mechanism

malfunction.

check valve malfunction.

(d) Air brake system leakage.

Available reservoir capacity may be

reduced by build-up of water, etc. Drain

and perform routine maintenance per Table

A, columns 3 & 4, on page A-3.

Go to Test 6 on page A-15.

Verify operation of air dryer. Follow vehicle

OEM maintenance recommendations and

component Service Data information.

Go to Test 2 on page A-14.

14.0 Air dryer

doesn’t purge.

(Never hear

exhaust from air

dryer.)

(a) Air dryer malfunction.

(b) Governor malfunction.

(d) Improper governor control line

installation to the reservoir.

Verify operation of air dryer. Follow vehicle

OEM maintenance recommendations.

Go to Test 4 on page A-15.

Go to Test 2 on page A-14.

Go to Test 5 on page A-15.

12.0 Air dryer

safety valve

releases air.

(a) Restriction between air dryer and

reservoir.

(b) Air dryer safety valve

malfunction.

performed.

(d) Air dryer malfunction.

(e) Improper governor control line

installation to the reservoir.

(f) Governor malfunction.

Inspect delivery lines to reservoir for

restrictions and repair as needed.

Verify relief pressure is at vehicle or

component manufacturer specications.

Replace if defective.

See Maintenance Schedule and Usage

Guidelines (Table A, column 3, on page

A-3).

Verify operation of air dryer. Follow vehicle

OEM maintenance recommendations and

component Service Data information.

Go to Test 5 on page A-15.

Go to Test 4 on page A-15.

13.0 Reservoir

safety valve

releases air.

(a) Reservoir safety valve

malfunction.

(b) Governor malfunction.

malfunction.

Verify relief pressure is at vehicle or

component manufacturer's specications

(typically 150 psi). Replace if defective.

Go to Test 4 on page A-15.

Go to Test 6 on page A-15.

Technician removes

governor.



Air dryer

safety valve



(b) is not applicable for the

compressor featured in this SD

sheet —- information is shown

for reference only.

A-13

Symptom: What it may indicate: What you should do:

This guide attempts to cover most com-

pressor system problems. Here are some

rare sources of problems not covered in

this guide:

• Turbocharger leakage. Lubricating

oil from leaking turbocharger seals can

enter the air compressor intake and give

misleading symptoms.

• Where a compressor does not have

a safety valve installed, if a partial or

complete discharge line blockage has

occurred, damage can occur to the con-

necting rod bearings. Damage of this kind

may not be detected and could lead to

compressor problems at a later date.

17.0 Compressor

leaks coolant

(a) Improperly installed plugs or coolant

line ttings.

(b) Damaged compressor head

gasket.

Inspect for loose or over-torqued ttings.

Reseal and tighten loose ttings and plugs

as necessary. If overtorqued ttings and

plugs have cracked ports in the head,

replace the compressor.

An air leak at the head gasket may indicate

a downstream restriction such as a freeze-

up or carbon blockage and/or could indicate

a defective or missing safety valve. Find

blockage (go to 9.0(f) for details) and then

replace the compressor. Do not re-use the

safety valve without testing. See Symptom

12.0(a).

If casting porosity is detected, replace the

compressor.

18.0 Noisy

compressor

(Multi-cylinder

compressors only)

(a) Damaged compressor. Replace the compressor.

Testing for leaks with

soap solution.

16.0 Compressor

leaks air

(a) Compressor leaks air at connections

or ports.

(b) Compressor unloader mechanism

malfunction.

gasket(s).

Check for leaking, damaged or defective

compressor ttings, gaskets, etc. Repair

or replace as necessary.

Go to Test 6 on page A-15.

An air leak at the head gasket(s) may

indicate a downstream restriction such as a

freeze-up or carbon blockage and/or could

indicate a defective or missing safety valve.

Find blockage (go to 9.0(f) for details) and

then replace the compressor. Do not re-

use the safety valve without testing. See

Symptom 12.0(a).

Other Miscellaneous Areas to Consider

(b) is not applicable for the

compressor featured in this SD

sheet —- information is shown

for reference only.



Head

gasket

locations



A-14

Tests

Exterior leaks at the head gasket are not a sign that oil is being passed into

the air charging system. Oil weepage at the head gasket does not prevent

the compressor from building air.

Observe the amount of weepage from the head gasket.

If the oil is only around the cylinder head area, it is acceptable (return the vehicle

to service), but, if the oil weepage extends down to the nameplate area of the

compressor, the gasket can be replaced.

Test 1: Excessive Oil Leakage at the

Head Gasket

Inspect for air leaks when working on a vehicle and

repair them promptly.

Park the vehicle on level ground and chock wheels.

Build system pressure to governor cut-out and allow

the pressure to stabilize for one minute.

Step 1: Observe the dash gauges for two additional

minutes without the service brakes applied.

Step 2: Apply the service brakes and allow the

pressure to stabilize. Continue holding for two

minutes (you may use a block of wood to hold the

pedal in position.) Observe the dash gauges.

If you see any noticeable decrease of the dash air

gauge readings (e.g. more than four psi, plus two psi

for each additional trailer) during either two minute

test, repair the leaks and repeat this test to conrm

that they have been repaired.

Air leaks can also be found in the charging system,

parking brakes, and/or other components - inspect

and repair as necessary.

Test 2: Air Brake System and Accessory Leakage

Caution: The temperatures used in this test

are not normal vehicle conditions.

Above normal temperatures can cause oil (as

vapor) to pass through the air dryer into the

air brake system.

This test is run with the engine at normal operating

temperature, with engine at max. rpm. If available,

a dyno may be used.

1. Allow the compressor to build the air system

pressure to governor cut-in.

2. Pump the brakes to bring the dash gauge

pressure to 90 psi.

3. Allow the compressor to build pressure from

95 to 105 psi gauge pressure and maintain

this pressure range by cycling the brakes for

ve (5) minutes.

4. Then, while maintaining max rpm and

pressure range, measure and record the

surface temperature of the ttings:

 at the compressor discharge port. (T1).

 at the air dryer inlet tting. (T2).

Use a touch probe thermocouple for measuring

the temperature.

5. See table below.

6. Re-test before returning the vehicle to service.

Test 3: Air Compressor Discharge

Temperature and Air Dryer Inlet

Temperature*

Compressor Air Dryer

Discharge Inlet

Fitting Fitting

Action

under under Temperatures are within

360°F 200°F normal range for this test, check

other symptoms. Go to 4.0 (h).

under over This could indicate a discharge

360°F 200°F line problem (e.g. restriction).

Call 1-800-AIR-BRAKE

(1-800-247-2725, option 2)

and speak with our Tech Team.

over __ Compressor is running hot.

360°F Check coolant 4(f) and/or

discharge line 4(g).

T1 T2

(* Note that only vehicles that have passed Test 2

would be candidates for this test.)

Discharge Line

Look

for

Weepage

A-15

1. Ensure that the governor control line from the

reservoir is located at or near the top of the res-

ervoir. (This line, if located near the bottom of

the reservoir, can become blocked or restricted

by the reservoir contents e.g. water or ice.)

Bendix® Compressors: Park vehicle, chock

wheels, and follow all standard safety procedures.

Remove the governor and install a tting to the

unloader port. Add a section of air hose (min

1 ft long for a 1/2" diameter line) and a gauge

to the tting followed by a shut-off valve and an

air source (shop air or small air tank). Open the

Test 5: Governor Control Line

Test 6: Compressor Unloader Leakage

1. Inspect control lines to and from the governor

for restrictions (e.g. collapsed or kinked).

Repair as necessary.

2. Using a calibrated external gauge in the supply

reservoir, service reservoir, or reservoir port

of the Bendix® D-2® governor, verify cut-in

and cut-out pressures are within vehicle OEM

specication.

3. If the governor is malfunctioning, replace it.

Tests (continued)

Test 4: Governor Malfunction

2. Perform proper reservoir drain intervals and air

dryer cartridge maintenance per Maintenance

Schedule and Usage Guidelines (Table A on

page A-3).

3. Return the vehicle to service.

shut-off and charge the unloader port by allowing

air pressure to enter the hose and unload the

compressor. Shut off the air supply and observe

the gauge. A steady reading indicates no leakage

at the unloader port, but a falling reading shows

that the unloader mechanism is leaking and needs

to be serviced.

Note: This Test is not applicable for the compressor

featured in this SD sheet —- information is shown for

reference only.

A-16

Drain contents of ALL air

tanks into Bendix® Basic™ cup

Bendix® Air System Inspection Cup (BASIC™)

Test Information

Appendix B: Information about the BASIC™ Test Kit (Bendix P/N 5013711)

* If the number of days since the air tanks were drained is unknown

- use the 30 day line.

** Note: Typical air dryer cartridge replacement schedule is every 3 yrs/

300K miles for low air use vehicles and every year/100K miles for high

air use vehicles.

*** To get an accurate reading for the amount of oil collected during

a 30 day period, ask the customer not to drain the air tanks before

returning. (Note that 30-90 days is the recommended air tank drain

schedule for vehicles equipped with a Bendix air dryer that is properly

maintained.) If, in cold weather conditions, the 30 day air tank drain

schedule is longer than the customer's usual draining interval, the

customer must determine, based on their experience with the vehicle,

whether to participate now, or wait for warmer weather. See the cold

weather tips in Bulletins TCH-008-021 and TCH-008-022 (included on

pages A-19-21 of this document).

****Note: After replacing a compressor, residual oil may take a

considerable period of time to be ushed from the air brake system.

Replace the Compressor. If under warranty, follow standard

procedures.

If, after a compressor was already replaced, the vehicle fails the

BASIC test again, do not replace the compressor**** - use the

Advanced Troubleshooting Guide to investigate the cause(s).

A-17

Footnote 1: Note: Typical air dryer cartridge replacement schedule is every 3 yrs/ 300K miles for low air use vehicles and every year/100K miles for

high air use vehicles.

Footnote 2: To get an accurate reading for the amount of oil collected during a 30 day period, ask the customer not to drain the air tanks before

returning. (Note that 30-90 days is the recommended air tank drain schedule for vehicles equipped with a Bendix air dryer that are properly maintained.)

If, in cold weather conditions, the 30 day air tank drain schedule is longer than the customer's usual draining interval, the customer must determine,

based on its experience with the vehicle, whether to participate now, or wait for warmer weather. See the cold weather tips in Bulletins TCH-008-021

and TCH-008-022 (included in Appendix B of the advanced troubleshooting guide).

Note for returning vehicles that are being

retested after a water/cloudy emulsion

mixture was found last time and the air

dryer cartridge replaced: If more than

one oil unit of water or a cloudy emulsion

mixture is found again, stop the BASIC test

and consult the air dryer's Service Data sheet

troubleshooting section.

* Note: A conﬁrmed complaint

above does NOT mean that

the compressor must be

replaced.

The full BASIC™ test below will

investigate the facts.

Customer’s Complaint Have you conﬁrmed complaint?

(Please check all that apply)

“Relay valve  leaks oil /  malfunctions”  no  yes*

“Dash valve  leaks oil /  malfunctions” no  yes*

 “Air dryer leaks oil”  no  yes*

 “Governor malfunction” no  yes*

 “Oil in gladhands”  no  yes*

how much oil did you ﬁnd? ________________________________

 “Oil on ground or vehicle exterior”  no  yes*

amount described: ______________________________________

 “Short air dryer cartridge life”

replaces every: ______________  miles,  kms, or  months

 “Oil in air tanks” amount described:_______________________

We will measure amount currently found when we get to step B of the test.

 “Excessive engine oil loss” amount described: ______________

Is the engine leaking oil?  no  yes*

Is the compressor leaking oil?  no  yes*

 Other complaint: _____________________________________

 No customer complaint.

Checklist for Technician



The Service Writer ﬁlls out these ﬁelds with information gained from the customer

The Service Writer

also checks off any

complaints that the

customer makes to

help the Technician

in investigating.

The Technician

checks boxes

for any of the

complaints that

can be conﬁrmed.

STEP A - Select one:

BASIC™ test starts here:

STEP B - Measure the Charging System Contents

The Technician selects the air use

category for the vehicle. This decides

which of the two acceptance lines on

the cup will be used for the test below.

For an accurate test, the

contents of all the air tanks on

the vehicle should be used.

Then go to Step B.

Number of Days Since Air Tanks Were Last Drained: ________ Date: ___________Vehicle #: ____________

Engine SN __________________________ Vehicle Used for: _______________Typical Load:________ (lbs.)

No. of Axles: ____ (tractor) ____ (trailer) No. of Lift Axles: ____ Technician’s Name: ____________________

 This is a low air use vehicle: Line haul (single trailer) with 5 or less axles, or

 This is a high air use vehicle: Garbage truck, transit bus, bulk unloader, or line

haul with more than 5 axles.

1. Park and chock vehicle on level ground. Drain the air system by

pumping the service brakes.

2. Completely drain ALL the air tanks into a single BASIC™cup.

3. If there is less than one unit of contents total, end the test now and

return the vehicle to service. Vehicle passes.

4. If more than one oil unit of water (or a cloudy emulsion mixture)

is found:

Otherwise, go to Step C.

Filling in the Checklist for the Bendix® Air System Inspection Cup (BASIC™) Test

Note: Follow all standard safety precautions. For vehicles using a desiccant air dryer.

Appendix B continued: Information about the BASIC™Test Kit (Bendix P/N 5013711)

(a) Change the vehicle’s air dryer cartridge

- see Footnote 1,

(b) Conduct the 4 minute leakage test (Step D),

again after 30 days - see Footnote 2. STOP

+ CK.

Oil

Units

A-18

Park the vehicle on level ground and chock wheels. Build system pressure to governor cut-out

and allow the pressure to stabilize for one minute.

1: Observe the dash gauges for two additional minutes without the service brakes applied.

2: Apply service brakes for two minutes (allow pressure to stabilize) and observe the dash

gauges.

If you see any noticeable decrease of the dash air gauge readings, repair leaks. Repeat this

test to conﬁrm that air leaks have been repaired and return vehicle to service. Please repeat

BASIC test at next service interval. Note: Air leaks can also be found in the charging system,

parking brakes, and/or other components - inspect and repair as necessary.

STEP E - If no air leakage was detected in Step D

STEP D - Air Brake System Leakage Test

STEP C - How to Use the BASIC™ Test

Sixty days since last air

tank draining Decision point

The Technician uses the chart (label) on the BASIC™

test cup to help decide the action to take, based on

the amount of oil found. Use the lower acceptance

line for low air use vehicles, and upper line for high

air use vehicles (from Step A).

If no air leakage was detected, and if you are conducting

this test after completing Step C, go to Step E.

BASIC Test Example

An oil level of 4 units in a sixty-day period is within the

acceptance area (at or below the line) for both low and

high air use vehicles. Return the vehicle to service.

1. Record days since air

tanks were last drained.



3. Action to

take

2. Record amount

of oil found:

If number of days is:

30-60 days (high air

use) or

30-90 days (low air

use)



if oil level is at or below

acceptance line for number

of days

if oil level is above

acceptance line for number

of days 

System OK.

Return to service.

Otherwise . . .



(if the number of days is

unknown, or outside the

limits above)

if oil level is at or below

30-day acceptance line 

if oil level is above 30-day

acceptance line 

STOP

TEST

Stop inspection.

Test again

after 30 days.

See Footnote 2.

_________ days _________ units

Go to Step D

System OK.

Return to service.

STOP

TEST

STOP

+ CK.

The Technician looks for the point where the number of

days since the air tanks were drained meets the oil level.

If it is at or below the (low or high use) acceptance line,

the vehicle has passed the test. If the point is above

the line then go to the leakage test. Air leakage is the number one

cause of compressors having

to pump excessive amounts of

air, in turn run too hot and pass

oil vapor along into the system.

Here the Technician conducts a

four-minute test to see if leakage

is a problem with the vehicle

being tested.

The Technician only reaches

Step E if the amount of oil

found, or the amount of time

since the air tanks were last

drained exceeds the acceptance

level, AND the vehicle passes

the four-minute leakage test

(no noticeable leakage was

detected).

Replace the compressor.

Note: If the compressor is within warranty period,

please follow standard warranty procedures. Attach

the completed checklist to warranty claim.

Filling in the Checklist for the Bendix® Air System Inspection Cup (BASIC™) Test

Note: Follow all standard safety precautions. For vehicles using a desiccant air dryer.

Appendix B continued: Information about the BASIC™Test Kit (Bendix P/N 5013711)

Oil

Level

Acceptance

Lines

A-19

Appendix C

Technical Bulletin

Bulletin No: Effective Date: Cancels: Page: 1 of

Subject:

TCH-008-021 3-5-2010 PRO-08-21 dated 2-6-2008 2

Air Brake System - Cold Weather Operation Tips

As the cold weather approaches, operators and eets alike begin to look to their vehicles with an eye toward

“winterization”, and particularly what can be done to guard against air system freeze-up. Here are some basic

“Tips” for operation in the cold weather.

Engine Idling

Avoid idling the engine for long periods of time! In addition to the fact that most engine manufacturers warn that

long idle times are detrimental to engine life, winter idling is a big factor in compressor discharge line freeze-up.

Discharge line freeze-ups account for a signicant number of compressor failures each year. The discharge

line recommendations under “Discharge Lines” are important for all vehicles, but are especially so when some

periods of extended engine idling can not be avoided.

Discharge Lines

The discharge line should slope downward from the compressor discharge port without forming water traps,

kinks, or restrictions. Cross-overs from one side of the frame rail to the other, if required, should occur as close

as possible to the compressor.

Dryer Inlet Temperature

The dryer inlet air temperature should typically be within the range of no more than 160°F and no less than 45°F

above low ambient (surrounding) temperature to prevent freeze-ups. (For example, if low ambient is minus

40°F, the dryer inlet must be above 5°F.) Lower dryer inlet temperatures should be avoided to minimize the risk

of freeze-up upstream of the air dryer. Higher temperatures should also be avoided to minimize the risk of heat

damage to the air dryer seals and to avoid a loss of drying performance.

Compressor Line Size

The line size and length is established by the vehicle manufacturer and should not be altered without the vehicle

manufacturers approval. As a reference, the line length from the compressor to the air dryer should be less than

16 feet and the minimum line sizes should be as follows:

Line Insulation

To guard against freez-ups in Low Duty Cycle applications, the discharge line can be insulated if it is greater

than 9 feet in length. The line can only be insulated back to 9 feet and a maximum of 3 feet. For example, if

the line is 10 feet, insulate the tting and the last one foot of the line. If the line is 15 feet, insulate the tting and

the last 3 feet of the line.

Minimum

Length

Minimum

I.D. Application

6 ft. 1/2 in. Low Compressor Duty Cycle Applications (0-20%)

10 ft. 5/8 in. High Compressor Duty Cycle Applications (20-40%)

A-20

Appendix C: Continued

Bulletin No.: TCH-008-021 Effective Date: 3/5/2010 Page: 2 of 2

System Leakage

Check the air brake system for excessive air leakage using the Bendix “Dual System Air Brake Test and Check

List” (BW1279). Excessive system leakage causes the compressor to “pump” more air and also reduce the life

of the air dryer desiccant cartridge.

Reservoir Draining (System without an Air Dryer)

Routine reservoir draining is the most basic step in reducing the possibility of freeze-up. All reservoirs in a

brake system can accumulate water and other contamination and must be drained! The best practice is to

drain all reservoirs daily if the air brake system does not include an air dryer. When draining reservoirs; turn

the ENGINE OFF and drain ALL AIR from the reservoir, better still, open the drain cocks on all reservoirs and

leave them open over night to assure all contamination is drained (reference Service Data Sheet SD-04-400 for

Bendix Reservoirs). If automatic drain valves are installed, check their operation before the weather turns cold

(reference Service Data Sheet SD-03-2501 for Bendix® DV-2™ Automatic Drain Valves). It should be noted that,

while the need for daily reservoir draining is eliminated through the use of an automatic drain valve, periodic

manual draining is still required.

Reservoir Draining (System with an Air Dryer)

Daily reservoir draining should not be performed on systems with an air dryer. This practice will cause the dryer

to do excessive work (e.g. build pressure from 0 -130 psi instead of the normal 110-130 psi).

Alcohol Evaporator or Injector Systems

Bendix Commercial Vehicle Systems LLC discourages the use of alcohol in the air brake system as a means

of preventing system freeze-up in cold temperatures. Studies indicate that using alcohol and alcohol based

products sold for this purpose removes the lubrication from the components of the air braking system. In

addition, the materials used for the internal seals of the air system components may be adversely impacted

by the residue that some anti-freeze additives leave behind. Both are detrimental to air system component life

expectancy, causing premature wear. Because of this, Bendix® air system components warranty will be void if

analysis shows that alcohol was added to the air brake system.

Alcohol is not an acceptable substitute for having adequate air drying capacity. If the air dryer is maintained in

accordance with the manufacturer’s recommended practices and moisture is found to be present in the system

reservoirs, more drying capacity is required. Bendix has several viable options including extended purge air

dryers, extended purge tandem dryers in parallel with common control, and air dryers arranged to provide

continuous ow as with the Bendix® EverFlow® continuous ow air dryer module. To address concerns with

contaminants in trailer air brake systems, the Bendix® Cyclone DuraDrain® water separator and the Bendix®

System-Guard® trailer air dryer are available. Refer to Bendix Technical Bulletin TCH-008-042 “Alcohol in the

Air Brake System” for additional information.

Air Dryers

Make certain air brake system leakage is within the limits stated in BW1279. Check the operation and function

of the air dryer using the appropriate Service Data Sheet for the air dryer.

Air Dryer Service Data Sheet

AD-2® air dryer SD-08-2403

AD-4™ air dryer SD-08-2407

AD-9® air dryer SD-08-2412

AD-IP® air dryer SD-08-2414

AD-IS® air dryer SD-08-2418

AD-IS® EverFlow® air dryer SD-08-2417

AD-SP® air dryer SD-08-2415

Cyclone DuraDrain® water separator SD-08-2402

PuraGuard® QC system lter SD-08-187B

Trailer System-Guard® air dryer SD-08-2416

Bendix literature is

available to order or

download on Bendix.com

A-21

Technical Bulletin

Bulletin No.: TCH-008-022 Effective Date: 1/1/1994 Page: 1 of 1

Subject: Additional Cold Weather Operation Tips for the Air Brake System

Last year we published Bulletin PRO-08-21 which provided some guidelines for “winterizing” a

vehicle air brake system. Here are some additional suggestions for making cold weather vehicle

operation just a little more bearable.

Thawing Frozen Air Lines

The old saying; “Prevention is the best medicine” truly applies here! Each year this activity accounts

for an untold amount of unnecessary labor and component replacement. Here are some Do’s and

Don’ts for prevention and thawing.

Do’s

1. Do maintain freeze prevention devices to prevent road calls. Don’t let evaporators or injectors run

out of methanol alcohol or protection will be degraded. Check the air dryer for proper operation

and change the desiccant when needed.

2. Do thaw out frozen air lines and valves by placing the vehicle in a warmed building. This is the

only method for thawing that will not cause damage to the air system or its components.

3. Do use dummy hose couplings on the tractor and trailer.

4. Do check for sections of air line that could form water traps. Look for “drooping” lines.

Don’ts

1. Do not apply an open ame to air lines and valves. Beyond causing damage to the internal

nonmetallic parts of valves and melting or burning non-metallic air lines. WARNING: THIS

PRACTICE IS UNSAFE AND CAN RESULT IN VEHICLE FIRE!

2. Do not introduce (pour) uids into air brake lines or hose couplings (“glad hands”). Some uids

used can cause immediate and severe damage to rubber components. Even methanol alcohol,

which is used in Alcohol Evaporators and Injectors, should not be poured into air lines. Fluids

poured into the system wash lubricants out of valves, collect in brake chambers and valves and

can cause malfunction. Loss of lubricant can affect valve operating characteristics, accelerate

wear and cause premature replacement.

3. Do not park a vehicle outside after thawing its air system indoors. Condensation will form in the

system and freeze again. Place the vehicle in operation when it is removed to the outdoors.

Supporting Air and Electrical Lines

Make certain tie wraps are replaced and support brackets are re-assembled if removed during routine

maintenance. These items prevent the weight of ice and snow accumulations from breaking or

disconnecting air lines and wires.

Automatic Drain Valves (System without Air Dryer)

As we stated last year, routine reservoir draining is the most basic step (although not completely

effective) in reducing the possibility of freeze-up. While automatic drain valves relieve the operator

of draining reservoirs on a daily basis, these valves MUST be routinely checked for proper operation.

Don’t overlook them until they fail and a road call is required.

Appendix D

Appendix E

Application Matrix for Bendix® 360cc Single Cylinder and 720cc Twin Cylinder

Compressors for International Maxxforce® Big Bore Engines

This useful Compressor Application Guide is a simple point system

using vehicle conguration and vocation options to help calculate the

Bendix® compressor right for your vehicle. Review items 1 – 13, ll in

the applicable points on each line, then refer to the application grid on the

next page for the Bendix compressor selections that can meet your vehicle’s

intended use. When completing the worksheet, if a particular entry is not

valid for your application, enter zero on that line. See the examples of how

to use this calculator at the end of the next page.

Note 1: Vehicles equipped with either bulk ofoading, central tire ination or used in City Transit bus applications are required to use a 720cc

compressor. No points need to be calculated. Refer to next page for proper compressor selection.

Note 2: It is recommended that a 720cc compressor be used on all Fire Truck and Aircraft Rescue applications to reduce the complexity of the “Fast

Fill” system.

Vehicle Conguration Points

1. Vehicle is equipped with bulk ofoading or central tire ination (See Note 1)

2. For every axle (tractor & trailer – including lifts): Add 1.0 point/axle 4

3. For each non-steerable lift axle (additional points): Add 1.0 point/axle 4

4. For each steerable lift axle (additional points): Add 0.5 points/axle 4

5. Tractor and/or trailer is equipped with air suspension Add 0.5 points 4

Vocation Options (Select the description that best ts)

6. Vehicle is used as a city transit bus (See Note 1)

7. Vehicle is used for pickup & delivery a) Non-fuel hauler:

add 0.5 points 4

b) Fuel hauler:

add 1.0 point 4

8. Vehicle is used for residential refuse

• Vehicle with a work brake Add 4.5 points 4

• Vehicle without a work brake Add 7.5 points 4

9. Vehicle is used for rural or commercial refuse Add 3.5 points 4

10. Vehicle is used as a yard or terminal jockey Add 7.5 points 4

11. Vehicle is a dump truck, a concrete mixer, or is used in

logging or construction Add 2.0 points 4

12. Vehicle is a re truck -- “Fast Fill” system (See Note 2) Add 6.0 points 4

13. Vehicle is used for line haul Add 0.0 points 40

Total Score

(Add lines 1 – 13 and use that sum on page two of this guide)

Appendix E

Compressor

Selections Point Totals

Bendix® 360cc

compressor

Bendix® 720cc

compressor

Points 2.5 3 4 5 6 6.5 7 8 9 9.5 10 11 12 13 14 15 16 or above

Certication to all applicable vehicle regulations is the sole responsibility of the vehicle manufacturer.

The application chart is for reference only. If your truck/tractor does not fall into these guidelines, please contact the

Bendix Compressor Engineering or Technical Services team at 1-800-AIR-BRAKE (1-800-247-2725, option 2).

Compressor Application Point

Total 360cc Single 720cc Dual

School Bus / RV / Air over Hydraulic any a

City Transit Bus / Highway Travel Coach / Express Route

Coach any a

School Bus Rural Route (No Auto Brake) any a

School Bus City Route (No Auto Brake) any a

Pick-up & Delivery

2.5 - 9 a

9.5 -13 a

Line Haul

3 - 6 a

6.5 - 9 a

9.5 - 13 a

Rural or Commercial Refuse 6.5 - 9 a

Rural or Commercial Refuse / Yard or Terminal Jockey 9.5 - 13 a

Residential Refuse (with Work Brake) 6.5 - 9 a

Residential Refuse (without Work Brake) 9.5 - 13 a

Concrete Mixer / Dump Truck /

Off-Highway / Construction / Logger

4 - 9 a

9.5 - 13 a

Fire Trucks

6.5 - 9 a

9.5 - 13 a

Bulk Off-loader any a

Central Tire Ination any a

This compressor application matrix offers directional information when sizing a Bendix compressor for the applicable vehicle vocation.

Testing should still be performed on the specic application to verify that the compressor remains within the 25% maximum allowable

duty cycle. This application matrix assumes that all compressor installations use an air induction system that is naturally aspirated.

The “Compressor Installation & Application Review” form explains the methods used to measure the vehicle’s duty cycle.

Dump

Furniture

Increasing Performance

Appendix E

Example #1: Typical Line Haul Application

A typical single axle, line haul vehicle:

• Air suspension

• Three (3) axles total

Vehicle Conguration

1. Not Applicable

2. Total number of all axles = 3 points

3. Total number of non-steerable lift axles = 0 points

4. Total number of steerable lift axles = 0 points

5. Tractor is equipped with air suspension = .5 point

Vocation Options

6, 7, 8, 9, 10, 11, 12 (Not Applicable) = 0 points

Total [ 3 + 0.5 = 3.5 points ]

Selection: Bendix® 360cc Air Compressors

Example #2: Line Haul Pulling Single Axle Double

A 4x2 line haul vehicle pulling:

• (2) single axle trailers

• (1) single axle dolly

• Tractor air suspension

• Five (5) axles total

Vehicle Conguration

1. Not Applicable

2. Total number of all axles = 5 points

3. Total number of non-steerable lift axles = 0 points

4. Total number of steerable lift axles = 0 points

5. Tractor is equipped with air suspension = .5 point

Vocation Options

6, 7, 8, 9, 10, 11, 12 (Not Applicable) = 0 points

Total [ 5 + 0.5 = 5.5 points ]

Selection: Bendix 360cc Air Compressors

Example #3: Bulk Gravel Hauler

A bulk gravel hauling vehicle:

• Two (2) non-steerable lift axles

• Truck equipped with air suspension

• Seven (7) axles total

Vehicle Conguration

1. Not Applicable

2. Total number of all axles = 7 points

3. Total number of non-steerable lift axles = 2 points

4. Total number of steerable lift axles = 0 points

5. Tractor is equipped with air suspension = .5 point

Vocation Options

6, 7, 8, 9, 10, 12, 13 (Not Applicable) = 0 points

11 (Vehicle is used as a dump truck/construction) = 2 points

Total [ 7 + 2 + 0.5 + 2 = 11.5 points ]

Selection: Bendix® 720cc Air Compressors

Example #4: Fuel Hauler (Not Equipped with Bulk Ofoading)

A fuel delivery vehicle:

• Air suspension

• One (1) non-steerable lift axle

• Seven (7) axles total

Vehicle Conguration

1. Not Applicable

2. Total number of all axles = 7 points

3. Total number of non-steerable lift axles = 1 point

4. Total number of steerable lift axles = 0 points

5. Tractor is equipped with air suspension = .5 points

Vocation Options

6 (Vehicle is used as a fuel hauler) = 1 point

7, 8, 9, 10, 11, 12, 13 (Not Applicable) = 0 points

Total [ 7 + 1 + 0.5 + 1 = 9.5 points ]

Selection choices include: Bendix® BA-922® Air Compressor

Printed on recy

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