Bendix Bw1425 Users Manual SD 01 503f

Bendix-Sd-01-503-Users-Manual-682441 bendix-sd-01-503-users-manual-682441

: Bendix Bendix-Bw1425-Users-Manual-651316 bendix-bw1425-users-manual-651316 bendix pdf

Open the PDF directly: View PDF .
Page Count: 4

1

SD-01-503

DESCRIPTION

The Bendix® D-2® governor, operating in conjunction with

the unloading mechanism, automatically controls the air

pressure in the air brake or air supply system between

a maximum (cut-out) pressure and a minimum (cut-in)

pressure. The compressor runs continually while the engine

runs, but the actual compression of air is controlled by the

governor actuating the compressor unloading mechanism

which stops or starts the compression of air when the

maximum or minimum reservoir pressures are reached.

D-2® governors are provided with mounting holes which

allow direct mounting to the compressor or remote

mounting.

Porting consists of three reservoir ports (1/8 inch P.T.),

three unloader ports (1/8 inch P.T.) and one exhaust port

(1/8 inch P.T.).

Bendix® D-2® Governor

EXHAUST

PORT

RESERVOIR

PORTS (3)

14

RETAINING

RING

11

PISTON

4

ADJUSTING

SCREW

2

BODY

6

EXHAUST

STEM

SPRING

FIGURE 1 - D-2® GOVERNOR

5

15

11

5

11

20

O-RING

CLEAR/BLACK

NONMETALLIC

WITH O-RING BLACK

RUBBER

BLUE

NONMETALLIC

FIGURE 2 - TYPES OF COVERS FIGURE 3 - TYPES OF PISTONS

16

UPPER SPRING

SEAT

1

RETAINING RING

15

RETAINING

RING

10

INLET/EXHAUST

VALVE

12

O-RING

13

WASHER

MOUNTING

HOLES

(2)

15

RETAINING

RING

7

FILTERS

9

INLET/EXHAUST

VALVE SPRING

5

EXHAUST

STEM

8

O-RING

12 O-RING

8 O-RING

19 LOWER

SPRING SEAT

19 LOWER

SPRING SEAT

10

INLET/EXHAUST

VALVE

11

PISTON

18

SPRING GUIDE

17

PRESSURE SETTING

SPRING

3

LOCKNUT

UNLOADER

PORTS (3)

COVER

9

INLET/EXHAUST

COVER VALVE

SPRING

NONMETALLIC METALLIC

2

OPERATION

Reservoir air pressure enters the D-2® governor at one of

its reservoir ports and acts on the piston and inlet/exhaust

valve. As the air pressure builds up, the piston and valve

move together against the resistance of the pressure

setting spring. When the reservoir air pressure reaches

the cut-out setting of the governor, the exhaust stem seats

on the inlet/exhaust valve, closing the exhaust passage,

and then opens the inlet passage. Reservoir air pressure

then fl ows around the inlet valve, through the passage in

the piston and out the unloader port to the compressor

unloading mechanism. Air also fl ows around the piston

which is slightly larger at the upper end. The added force

resulting from this larger area assures a positive action

and fully opens the inlet valve.

As the system reservoir air pressure drops to the cut-

in setting of the governor, the force exerted by the air

pressure on the piston will be reduced so that the pressure

setting spring will move the piston down. The inlet valve will

close and the exhaust will open. With the exhaust open, the

air in the unloader line will escape back through the piston,

through the exhaust stem and out the exhaust port.

PREVENTIVE MAINTENANCE

Important: Review the Bendix Warranty Policy before

performing any intrusive maintenance procedures. A

warranty may be voided if intrusive maintenance is

performed during the warranty period.

No two vehicles operate under identical conditions, as

a result, maintenance intervals may vary. Experience is

a valuable guide in determining the best maintenance

interval for air brake system components. At a minimum,

the D-2® governor should be inspected every 6 months

or 1500 operating hours, whichever comes first, for

proper operation. Should the D-2® governor not meet the

elements of the operational tests noted in this document,

further investigation and service of the governor may be

required.

SERVICE TESTS

OPERATING TESTS

Start the vehicle engine and build up air pressure in the air

brake system and check the pressure registered by a dash

or test gauge at the time the governor cuts-out, stopping the

compression of air by the compressor. The cut-out pressure

should be in accordance with the pressure setting of the

piece number being used. (Common cut-out pressures are

between 105-125 psi.) With the engine still running, make

a series of brake applications to reduce the air pressure

and observe at what pressure the governor cuts-in the

compressor. As in the case of the cut-out pressure, the

cut-in pressure should be in accordance with the pressure

setting of the piece number being used. (Common cut-in

pressures are between 90-105 psi.)

Never condemn or adjust the governor pressure settings

unless they are checked with an accurate test gauge

or a dash gauge that is registering accurately. If the

pressure settings of the D-2® governor are inaccurate

or it is necessary that they be changed, the adjustment

procedure follows. Note: If the governor cover is marked

nonadjustable and the adjusting stem has been sheared

off, this is a non-serviceable governor and must be replaced

with a new or remanufactured unit.

A. Remove the top cover from the governor.

B. Loosen the adjusting screw locknut.

C. To raise the pressure settings, turn the adjusting screw

counter-clockwise. To lower the pressure settings, turn

the adjusting screw clockwise. Note: Be careful not

to over adjust. Each 1/4 turn of the adjusting screw

raises or lowers the pressure setting approximately

4 psi.

D. When proper adjustment is obtained, tighten the

adjusting screw locknut and replace the cover.

(Note: The pressure range between cut-in and cut-out is

not adjustable.)

LEAKAGE TEST

Leakage tests on the D-2® governor should be made in

both cut-in and cut-out positions.

CUT-IN POSITION

Apply soap solution around the cover and to the exhaust

port. Slight bubble leakage permitted. Excessive leakage

indicates a faulty inlet valve or lower piston o-ring.

CUT-OUT POSITION

Apply soap solution around the cover and to the exhaust

port. Slight bubble leakage permitted. Excessive leakage

indicates a faulty exhaust valve seat, exhaust stem o-ring,

or o-ring at the top of the piston.

If the governor does not function as described or leakage is

excessive, it is recommended that it be replaced with a new

or remanufactured unit, or repaired with genuine Bendix

parts available at authorized Bendix parts outlets.

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 general precautions should be observed

at all times.

1. Park the vehicle on a level surface, apply the

parking brakes, and always block the wheels.

Always wear safety glasses.

3

2. Stop the engine and remove 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.

3. 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.

4. 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

an AD-IS® air dryer system or a dryer reservoir

module, be sure to drain the purge reservoir.

5. Following the vehicle manufacturer’s recommended

procedures, deactivate the electrical system in a

manner that safely removes all electrical power

from the vehicle.

6. Never exceed manufacturer’s recommended

pressures.

7. 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.

8. Use only genuine Bendix® replacement parts,

components and kits. Replacement hardware,

tubing, hose, fi ttings, etc. must be of equivalent

size, type and strength as original equipment and

be designed specifi cally for such applications and

systems.

9. Components with stripped threads or damaged

parts should be replaced rather than repaired. Do

not attempt repairs requiring machining or welding

unless specifi cally stated and approved by the

vehicle and component manufacturer.

10. Prior to returning the vehicle to service, make

certain all components and systems are restored

to their proper operating condition.

11. 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.

REMOVING AND INSTALLING

REMOVING

1. Block and hold vehicle by means other than air

brakes.

2. Drain air brake system.

3. If the governor is compressor-mounted type, disconnect

reservoir air line. If the governor is remote-mounted,

disconnect both the unloader and reservoir air lines.

4. Remove governor mounting bolts, then governor.

Caution: Prior to disassembly, it is required to have the

proper maintenance kit available to replace parts to be

discarded during disassembly.

DISASSEMBLY

1. Clean the governor exterior of dirt and grease.

2. If the governor cover is marked nonadjustable and the

adjusting screw has been sheared off, this is a non-

serviceable governor and must be replaced with a new

or remanufactured unit.

3. If the governor has a blue nonmetallic cover, (refer to

Figure 2) hold governor with one hand, with the other

hand grip cover from the top and pull up with thumb until

cover disengages from the governor body. If top cover

on governor is made of rubber or clear nonmetallic

material unscrew cover until it releases from the

adjusting screw (4) of governor. Remove o-ring (20,

Figure 2) if present. Note: O-ring (20) is used on Hi-

Temp and waterproof governors only.

4. With a pair of retaining ring pliers, remove the spring

assembly retaining ring (1) and save.

5. Pull the adjusting screw (4) and spring assembly out

of the governor body (2).

Note: Disassembly of the spring assembly normally is

not required. (Reuse and do not wash the assembly

because lubrication may be removed.) If Disassembly

of the spring assembly is necessary, the following

instructions apply; otherwise, proceed to Step 6.

Remove the lock nut (3), then the hex-shaped upper

spring seat (16) from the adjusting screw (4). Remove

the pressure setting spring (17), lower spring seat (19),

spring guide (18) and the other lower spring seat (19)

from the adjusting screw (4).

6. Gently tap the open end of the valve body on a fl at

surface to remove the exhaust stem (5), the exhaust

stem spring (6), and piston assembly (11). Items 5 and

11 may be made of metal or nonmetallic material.

7. Remove and discard the two o-rings (8) on the piston

O.D. and with a hooked wire remove and discard the

o-ring (12) from the piston l.D. On nonmetallic piston,

washer (13) and retaining ring (14) may be removed

to facilitate removal of o-ring (12).

4

8. If piston assembly is nonmetallic (Figure 3), use a small

screwdriver and carefully insert blade of screwdriver

between two of the ears of the retainer ring in the

bottom of the piston (11) and pry retainer ring (15) out

of the piston and discard. Remove inlet/exhaust valve

spring (9) and the inlet/exhaust valve (10) and discard.

If piston assembly is metallic, disengage inlet/exhaust

valve spring (9) from recess in bottom of piston (11),

remove inlet/exhaust valve spring (9), and the inlet

exhaust valve (10) and discard.

9. Remove and discard fi lters (7) from unloader and

reservoir ports in governor body.

CLEANING AND INSPECTION

1. Clean all remaining parts in mineral spirits.

2. Inspect body for cracks or other damage. Be particularly

careful that all air passages in the body, exhaust stem,

and piston are not obstructed.

3. Check springs for cracks, distortion, or corrosion.

4. Replace all parts which are worn or damaged.

ASSEMBLY

Prior to assembly, lubricate the two lower body bores, all

o-rings and o-ring grooves with lubricant provided. Note:

Also spring guide and adjusting screw (if disassembled).

1. Install o-ring (12) in piston (11). Replace washer (13)

and retaining ring (14) on nonmetallic piston if removed

during disassembly.

2. Drop the inlet/exhaust valve (10) into place at the

bottom of the piston (11).

3. Nonmetallic Piston: Install the inlet/exhaust valve spring

(9) with the small end against the valve, place the

retaining ring (15) on top of the large end of the valve

spring (9) [concave side of retaining ring (15) facing

away from piston (11)], press into piston with thumb,

making sure ears of retaining ring (15) are seated into

piston (11) as far as possible.

Note: Do not use a press or hammer to install retaining

ring. Excessive force may damage the piston.

Metallic Piston: Install the inlet/exhaust valve spring (9)

with the small end against the valve. Press the spring

down until the larger coiled end snaps into the recess

inside the piston (11).

4. Install the piston o-rings (8) on the piston (11).

5. Install the exhaust stem spring (6) in the piston (11)

with the large coil end next to the piston.

6. Install the exhaust stem (5) through spring (6) and into

piston (11).

7. Install assembled piston (11) into the governor body

(2).

8. If the spring assembly was not disassembled, proceed

to Step 9. If the spring assembly was disassembled,

the following instructions apply: install on the adjusting

screw (4) in this order; lower spring seat (19), spring

guide (18), spring seat (19), pressure setting spring

(17), hex-shaped upper spring seat (16). Screw the

upper spring seat onto the adjusting screw until the

distance from the top of the seat to the bottom of the

adjusting screw head is approximately 1-7/8 inches.

Install the lock nut (3).

9. Install the adjusting screw (4) and spring assembly into

the governor body (2).

10. Install retaining ring (1) making certain that it seats

completely into the groove in the governor body (2).

If cover provided in kit is black rubber, (refer to Figure

2) install by pushing it onto the adjusting screw.

If cover provided in kit is clear nonmetallic, install o-ring

(20) and screw cover onto the adjusting screw. Tighten

until cover bottoms on governor body. Note: O-ring (20)

is used only on Hi-Temp and waterproof governors. If

cover provided in kit is blue nonmetallic place cover

over one edge of top of governor; with index fi nger

catch knob on top of cover and pull until cover snaps

into place.

Note: Nonmetallic cover should be at room temperature

for ease of assembly. Do not attempt to force cover on

square to the governor body.

11. Install fi lters (7) in governor body. The head of a pencil

makes a satisfactory installation tool.

INSTALLATION

1. If the governor is compressor-mounted, clean the

mounting pad on both the compressor and governor.

Clean connecting line, or lines. Be certain the unloading

port is clear and clean. If the governor is mounted remotely,

it should be positioned so that its exhaust port points

down. It should be mounted higher than the compressor

so that its connecting lines will drain away from the

governor.

2. Install governor.

3. If compressor-mounted type, use the governor mounting

gasket provided.

4. Connect air lines to governor.

5. Perform operating and leakage tests as outlined under

Service Tests section.

BW1425 © 2010 Bendix Commercial Vehicle Systems LLC. All rights reserved. 5/2010 Printed in U.S.A.