user manual
Aeris Installation, Service and Troubleshooting Manual
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STEMCO Aeris
Installation Manual
Date: 5/29/2012
Rev: A
• AerisTM by STEMCO, an advanced automatic tire inflation system based on patented rotary sealing
technology and precision electronic airflow detection. The system is designed to keep commercial
trailer tires properly inflated using air pressure from the trailer’s braking system.
• The rotary seal employed in AerisTM by STEMCO differs dramatically from currently available systems
and is targeted to increase the reliability and durability of these components substantially. The rotary
seal in an automatic tire inflation system is a critical component – it prevents the higher pressures
needed to inflate commercial tires (typically 100 psi) from leaking into the wheel end, which can
handle no more than 6 psi. Excess pressure can cause the wheel end seal to fail prematurely,
causing lubricants to exit the hub and leaving moving parts susceptible to wear and seizure – a
dangerous scenario. In addition to the high reliability and durability of the patented sealing system,
AerisTM by STEMCO also includes several one-way pressure relief valves per axle to ensure that the
wheel-end is never pressurized.
• AerisTM by STEMCO also includes a very sensitive electronic flow detection technology capable of
informing the driver whether the system is making a minor adjustment to tire pressure or if a major
leak is present. A “Smart Sense” wheel end identification option will inform the driver which wheel
end is taking air – saving time and labor in the search and repair of tire leaks.
• AerisTM by STEMCO represents a leap forward in automatic tire inflation technology. STEMCO starts
with an unwavering commitment to increase the safety of our roadways by protecting the wheel end
from damaging air pressure, and then added several additional safeguards and features. Aeris
augments our BatRF tire pressure monitoring systems to complete our suite of tire pressure
management solutions.
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General View of Aeris Components Installed.
Refer to this installation guide on how to install the Aeris system on trailers.
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Table of Contents
General Information…………………………………………………………………………….5
About this Manual………………………………………………………………………..5
Explanation of Signal Words……………………………………………………………5
Important Safety Notices………………………………………………………………..5
General Service Information……………………………………………………………6
General Service Installation Note……………………………………………………...6
Contact STEMCO………………………………………………………………………….7
Literature Link…………………………………………………………………...7
Phone…………………………………………………………………………….7
System Overview……………………………………………………………………………….7
Aeris Overview…………………………………………………………………………..7
System Features………………………………………………………………………...7
Aeris Specifications……………………………………………………………………..8
System Operation……………………………………………………………………….8
How System Works……………………………………………………………8
System Components……………………………………………………………………9
Recommended Tool List………………………………………………………………..9
Aeris Installation................................................................................................................9
Trailer Preparation………………………………………………………………………9
Axle Preparation…………………………………………………………………………10
Drain Oil………………………………………………………………………….10
Remove Welsh Plug……………………………………………………………11
Drill Fixture (How to Make) and Use…………………………………………12
Drill & Tap Holes in Axle………………………………………………………12
Clocking Wheels………………………………………………………………………..16
Axle Hose Installation………………………………………………………………….18
Split Loom Tubing Protection Installation……………………………………………18
Center Vent Line Installation………………………………………………………….19
Axle Plug Installation…………………………………………………………………..20
Aeris Hubcap Assembly Installation………………………………………………….21
Control Box Installation………………………………………………………………...24
Connecting Airlines to Control Box…………………………………………………...26
Air Lines to Compressed Air Tank……………………………………………29
Tire Hose Installation…………………………………………………………………...31
Light Kit and Wiring Installation……………………………………………………….32
Decal Location………………………………………………………………………….39
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System Installation Check…………………………………………………………………40
Maintenance………………………………………………………………………………….41
Check Tire Pressure…………………………………………………………………41
Regulator Setting…………………………………………………………………….42
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General Information
About This Manual
This manual is provided to support the STEMCO Aeris tire inflation system. The manual provides the
following information needed to install service and troubleshoot the Aeris system.
Explanation of Signal Words
Please pay attention to special symbols used through this manual to convey important information.
Hazard signal words such as DANGER, WARNING, CAUTION, or NOTICE are used throughout this
manual. Information accented by these words indicates a point of emphasis of importance. The
following definitions comply with ANSI Z535.4 and indicate the use of signal words as they appear
within this manual.
! DANGER: Indicates immediate hazards which will result in severe personal injury or death.
! WARNING: Indicates hazards or unsafe practices which could results in sever personal injury
or death.
! CAUTION: Indicates a hazardous situation which, if not avoided, could result in minor or
moderate injury.
NOTICE: Indicates hazards or unsafe practices which could result in damage to machine or
equipment.
IMPORTANT: An operating procedure, practice or condition that is essential to emphasize.
! Safety alert symbol used to indicate a condition exists that may result in personal injury or harm to
individuals. It must be applied to DANGER, WARNING and CAUTION statements which emphasize
severity.
IMPORTANT: Please pay special attention to the information supplied in the Explanation of Signal
Words section. These words are used to help prevent immediate hazards, unsafe practices, sever
personal injury or death and damage to machines or equipment.
Important Safety Notices
• Proper maintenance, service and repair are important to the operation and reliability of the trailer
suspension system and its components. The procedures recommended by STEMCO as described in
this manual are methods of performing maintenance, inspection, repair and service. All warnings and
cautions should be read carefully to help prevent personal injury and to help assure proper installation
methods are used.
• Improper maintenance, service and repair can result in personal injury, vehicle damage, property
damage, unsafe operating conditions or void the manufacturer’s warranty.
• Carefully read, understand and follow all safety related information in this manual.
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! WARNING: DO NOT modify or rework parts. Use only STEMCO Aeris authorized replacement
parts. Use of substitute, modified or replacement parts not authorized by STEMCO may not
meet STEMCO’s specifications. This may cause the part to fail which could result in loss of
vehicle control and possible personal injury or property damage. Do not modify parts without
STEMCO’s authorized written permission.
! WARNING: Always wear proper PPE when installing and performing maintenance repair,
servicing equipment or cleaning tractor or trailer components.
! WARNING: Solvent cleaners can be flammable, poisonous and can burns or serious injury.
To help avoid serious personal injury, carefully follow the manufacturer’s product instructions
and guidelines. Please follow the procedures below:
• Wear proper eye protection
• Wear proper protective clothing to protect your skin
• Always work in well ventilated area
• Do Not use gasoline, or solvents that contain gasoline. Gasoline can explode and cause
serious personal injury or death.
• Hot tank solutions or alkaline solutions must be used correctly. Follow the manufacturer’s
product instructions and guidelines.
! WARNING: Avoid creating dust from brakes when cleaning around any brake components.
Dust from brake pads and/or parts is a possible cancer and lung disease hazard.
General Service Information
Before starting any work or installation, read, understand and comply with the following:
• Read all instructions and procedures.
• Company’s service, maintenance, installation and troubleshooting procedures.
• Manufacturer’s vehicle safety instructions when working on the vehicle.
• Manufacturer’s vehicle instructions not detailed in this service manual.
• Follow all local safety regulations and best safety practices when installing.
General Service Installation Notes
• Work must be performed by trained personnel.
• Use all recommended tools required to help avoid personal injury and damage to components.
• Be aware of potential power release of tensioned springs on brake chamber or the brake return
springs. The release of tension can cause injury.
• After installation perform operational checks and test the trailer to make sure the brakes are
functioning properly before releasing back into service.
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Contact STEMCO
STEMCO reserves the right to make changes and improvements to our products and literature at
anytime. Please view STEMCO website for the latest version of this manual.
www.STEMCO.com/library/installation-instructions.
STEMCO LP
300 Industrial Blvd.
Longview, Texas 75602
P.O Box 1989
Longview, Texas 75606-1989
Phones: (800) 527-8492 | (903) 758-9981
FAX: (800) 874-4297 | (903) 232-3508
System Overview
• The Aeris tire inflation system is designed to automatically inflate tires that are below the target
pressure setting. The system uses air from the trailer’s compressed air tank. The compressed air
tank pressure setting must be higher than the targeted tire pressure setting. Failure to have the
air tank pressure above the target tire pressure prevents proper operation of the inflation system.
System Features
• Tire pressure is continuously monitored and adjusted automatically to the target tire pressure.
• Adjustable air pressure regulator is used for setting desired tire pressure target.
• An indicator light will illuminate when air is flowing to the tires.
• Does not pressurize axle tube (prevent contamination of seals).
• Rotary seal air leakage will not enter the wheel end, preventing oil contamination on the hubcap.
• Each wheel end has dual venting paths to prevent wheel end pressurization.
• Checks tire pressure constantly.
• Integrated check valves in the hoses isolate tires from system if a tire is damaged or leaking.
• Tire pressure check ports are integrated into each hose, eliminating the need to remove the hose
to check the tire pressure.
• An air filter is provided on the inlet air line to prevent particulates from clogging the system.
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Aeris Specifications
• Tire pressure setting range: 70-120 psi
• Pressure check interval: Continuously supplies air to tires
• System power requirements at 12VDC: < 12W.
• Minimum power requirement to operate: 9 Volts
• Indicator light current range: 50 mA to 600 mA
• Tire inflation capacity (per tire): 10 psi in 2-3 minutes
• The indicator light provides the following system information:
• No light: System is good
• Power up: Light blinks three times
• No pressure: Long flash followed by 2 blinks repeating.
• Low volume flow: Constantly on
• High volume flow: Blinking constantly
System Operation
How System Works
• The Aeris tire inflation system is designed to continuously supply filtered, regulated compressed
air to each tire on the trailer. There is no operation required of the driver for the system to function
normally. The only requirement of the driver is to verify the indicator lamp is functioning and to
monitor the system periodically.
• The Aeris system is preset to maintain a specific tire pressure in each tire. The pressure in the
trailer’s air tank must be maintained above the targeted pressure to allow the controller to
continuously supply and maintain the preset tire pressure to all tires.
! IMPORTANT: For Aeris controller to operate properly the air tank pressure must be greater
than the tire pressure target. The controller cannot supply tire pressure above the air tank
pressure.
• When the system is operating properly, the air tank will supply pressurized air to the Aeris
controller. The controller will supply regulated compressed air to the air lines going to each tire. If
a tire is low, air from the trailer air tank will inflate the tire until the targeted tire pressure is
achieved. Regulated air flowing from the controller to the air lines and tires may cause the
indicator light to remain on until the target pressure is reached. Constant pressure remains and is
maintained in air lines and tires at the targeted pressure.
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• If a tire is leaking or there is a leak in the lines, the indicator light may illuminate and stay on. If the
indicator light stays on for more than 10 minutes, the system is attempting to inflate the tire or
trying to correct for the air line loss to the targeted air pressure. If this happens, the operator
should stop and check the tires manually to determine if it’s safe to continue to operate the
vehicle. Operator should seek service at the next available opportunity.
• Remaining tires are protected from pressure loss by check valves integrated into each tire hose.
System Components List
• Hubcaps
• Spindle plug driver and plugs
• Air lines and fittings
• Light indicator and electrical wiring
• Control box with regulator and filter
• Control box mounting bracket
• Flexible wiring conduit
• Hardware kit
Recommended Tool List
• 3/8” Drill
• Drill Bushings (Type SF) K, 7/16” and 9/16”
• Drill Bits K, 7/16” and 9/16”
• Medium to Heavy Duty Extension Cord
• Wire Strippers
• Wire Crimper
• Combination Wrenches – 1/2", 9/16” and 11/16”
• Hammer
• Drill Fixture (See page 12)
• Ratchet and Sockets - 1/2", 9/16” and 11/16”
• #2 Phillips Screwdriver Bit for Drill
• Cutting and Tapping Fluid
• 10” Adjustable Wrench (Crescent)
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Aeris Installation
Trailer Preparation
! WARNING: Before starting any work on trailer, park trailer on a level surface. Chock all
wheels in front and back of each wheel to prevent the trailer from moving. Support the
trailer with safety jack stands. Do Not work under vehicle supported by jack stands only!
Jacks can slip and fall over. Serious personal injury or damage to components can result.
See Figure 1
! WARNING: To prevent serious eye injury, always wear approved safety glasses when
performing trailer maintenance and service.
Figure 1
• Park trailer on level surface.
• Set trailer parking brake.
• Chock each trailer wheel.
• Place jack stands under trailer.
• Bleed braking system of compressed air.
Axle Preparation
Drain Oil
• Place drain pan under hubcap for oil.
• Remove bolts from all hubcaps and allow oil to drain from each wheel end.
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Drain Pan Drain oil into pan from each wheel
Welsh Plug Removal
• Remove welsh plugs. Drill a small hole off center in welsh plug. Hole should be smaller than plug
removal spear on the end of slide hammer. Using a slide hammer fitted with a welsh plug removal
spear to remove the welsh plug. Be careful not to score the inside diameter of the spindle bore.
• If you do not have a slide hammer you may be able to remove the welsh plug by using a chisel
and hitting the welsh plug off center. This should cause the plug to start turning inside the spindle
unless there is a shoulder behind the welsh plug. Once the plug has turned enough to grab it with
a pair of pliers and pull until plug comes out.
• If plug cannot be removed, drill a 1/2” hole in the welsh plug. Make sure as you are drilling the
hole you don’t score the inside diameter of the spindle bore.
• Insert a long steel rod into the 1/2" hole until it hits the back side of the welsh plug in the opposite
spindle. Steel rod must be longer than the length of the axle. Use a hammer to hit the rod and
knock the welsh plug out. Pull rod out and repeat procedure on the plug with hole with the 1/2"
hole in it. Repeat procedure for second axle. See Figure 2
Drill hole off center for slide hammer or rod. Rod running through axle to other welsh plug
Figure 2
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• Cover bearings and axle nut with clean towel to prevent contamination.
• Inspect the spindle bore for burrs. Remove any burrs using straight die grinder with light grade
flapper sanding wheel. Clean the bore of any grinding debris.
• Check inside spindle to verify that the axle is hollow, which is required for air line passage.
Drill Fixture (Suggested)
Drill fixture for aligning holes on axle.
1. Drill fixture
2. Drill bushing lock screw
3. Drill bushings - Type SF (3 Sizes) - K,
7/16” and 9/16”.
Figure 3 Figure 4
Determine Axle Requirements:
• Axle with nothing installed – Start at “Drill and Tap Hole”.
• Axles with pre-drilled holes but no hardware installed – Start at “Axle Hose Installation”
• Axle with “Other” tire inflation system – remove airlines and fittings– Start at “Axle Hose
Installation”
Drill and Tap Holes
• Clean off axle for drilling holes for air fittings.
• Review the sketch of how drill fixture is made. See Figure 3 & 4
• Drill holes using the drill fixture (Figure 4) to help facilitate in the drilling and tapping of the three air
fittings. Use small level and c-clamp to hold fixture in place. Use drill lubricant for holes.
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! WARNING: The use of a drill fixture is recommended. Drilling free hand can create oblong
holes. Drilling should be done at a medium speed. Keep drill straight when boring holes.
Tapping should be done by hand only. Do not use a drill for tapping. The use of a drill to
tap holes can lead to threads being too deep or breaking the tap.
! WARNING: When drilling the 7/16” hole, be careful as the drill bit breaks through the inside
of the axle! The drill bit can hang up causing the drill to twist in your hands. When
breaking through the inside of the axle, apply less pressure and drill at a slower speed.
• Use either an angle drill or standard drill where room permits. Use lubricant for drilling and
tapping holes. With drill fixture is in place (Figure 5) insert the “K” drill bushing in fixture and drill a
pilot hole using a “K’ drill bit. Next insert the 7/16” bushing and drill the hole using a 7/16” drill bit.
Next insert the 9/16” bushing in fixture and using a 1/4-18 NPT tap the hole. Repeat procedure on
all 3 holes in each trailer axle. When tapping holes leave approximately 6-7 threads sticking out of
the axle. STEMCO recommends using an L1 plug gage to measure proper depth. Do not run tap
all the way into the axle.
! WARNING: When finished drilling holes, use a cleaning wand connected to high pressure
air to blow out shavings from inside of the axle. Use safety glasses.
1. Axle
2. Torpedo Level
3. C-Clamp
4. Drilling Fixture
Note:
Before drilling any holes in axle make sure they will
not interfere with any suspension components or
brake components. Contact STEMCO for technical
assistance at 903-758-9981 in U.S.A.
Figure 5
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Axle Manufacturer Type Location A Location B
Hendrickson INTRAAX / VANTRAAX
See Figure 6 See Figure 6
Hendrickson TRLAXLE See Figure 7 See Figure 7
SAF Holland TAPER See Figure 8 See Figure 8
AXN Tiremaxx TIS See Figure 7 See Figure 7
AXN Trax-Pro 50 See Figure 9 See Figure 9
Meritor See Figure 7 See Figure 7
Figure 6
Figure 7
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Figure 8
Figure 9
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Component Installation Instructions
• Wheels on each wheel end (dual tires) must have the valve stems clocked approximately 180°
apart for installation of airlines to Aeris hubcap and valve stems on tires. Clocking should be done
prior to installing Aeris system. See Figure 10
Clocking Wheels
• Clocking dual wheels is important. Proper clocking allows the inner and outer valve stems to align
with the hose attachment fittings on the Aeris hubcap. Wheels with 2 hand holes can be clocked
so the valve stems are exactly 180° apart, but the valve stems on 5 hand holes cannot clocked
exactly 180° apart. It may be necessary to remove the outer tire and rotate it to clock wheels
properly.
Figure 10
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Figure 11
Dual wheels with 2 hand holes, or aluminum wheels with small round valve stem clearance
holes require a second alignment procedure to ensure the hoses will not touch the wheel. To
ensure perfect alignment between the hose attachment fittings on the hubcap and valve
stems, the wheels may need to be rotated one stud clockwise or counterclockwise. See
Figure 11.
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Axle Hose Installation
! WARNING: Before pushing the air line tubing into the axle, disassemble the pass through
fitting and place the components over the end of the air line in this order: See Figure 12
• Pass Through Cap
• Rubber O-Ring
• Pass Through Fitting Body
Now place a piece of masking tape over the end of the air line or plug the end of it so no
debris can get inside the line as it is being pushed through the axle towards the wheel
end.
Figure 12
• Push the cap, o-ring and pass through fitting back far enough back on air line to have enough air
line to push through tapped hole without getting in your way.
• Route the air line through the axle towards the spindle end on each of the outer tapped holes until
air line is protruding approximately 8” out of the spindle. If air line hangs up inside the axle, you
may need to use something to help fish it through the spindle end. Make sure the air line doesn’t
have any kinks in it.
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Split Loom Tubing Protection Installation
• Place one of the supplied split loom tubing protection sleeves over the air line tubing of each
spindle end to help protect against sharp edges inside the axle. Repeat steps 1-4 on remaining
axle wheel ends.
• The air line from the spindle end going to the fitting on the axle fitting can now be cut. Make sure
to cut the tubing long enough to reach just past the center of the axle. The air line will be attached
to a tee fitting and then tie-wrapped to the center axle vent line. See Figure 13
Center Vent Line Installation
• Install the push lock fitting (1/4” NPT x 3/8” tubing) into the center tapped hole and tighten. Insert
the supplied 37” X 3/8” nylon tubing with the duck-bill into the fitting. The vent line should be
oriented so the duck bill is pointing up and tie-wrap it to frame or hoses of trailer where it’s not
going to be part of any moving component. If this option is not possible the vent line can be
routed around the axle. Make sure the tubing goes around the axle 1-2 times.
• Tie wrap and secure the end of the air line with the duck bill to the air line coming out of the axle.
Make sure the duck bill vent is facing in a up and there aren’t any big loops of air line hanging
down under the axle to grab on anything as trailer is moving. Repeat this step on all axles where
Aeris is being installed.
Figure 13
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Axle Plug Installation
• Install the axle plug using the axle plug installation tool. The tubing passes through the center of
the axle plug which is then inserted into the hole on the installation tool. Align the axle plug with
the axle spindle and push leading edge of axle plug into spindle bore.
• Now place the face of the installation tool against the axle plug and using a hammer gently hit the
handle of the installation tool and seat the axle plug flush with the end of the spindle end. Be
careful to drive the axle plug in as straight and even as possible to keep plug from being cocked in
bore. Repeat this step on remaining axle wheel ends. Small amount of wheel end lubricant can
be applied to the rubber to help aid in installing axle plug.
• Using a tubing cutter square the end of the air line coming out of the axle after removing the
masking tape. Leave 5-6” of tubing sticking out of the spindle for easier installation of the Aeris
hubcap. See Figure 14
Figure 14
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Aeris Hubcap Assembly Installation
• Place the hubcap gasket over the tubing before inserting it into push lock fitting on hubcap. If you
are installing a grease application hubcap, make sure to follow recommended manufacturing
guidelines for putting grease in bearings before you install the hubcap.
! IMPORTANT: Make sure grease is applied before installing grease hubcap if hubcap is a grease
application.
• Install the tubing into the push lock fitting on the Aeris hubcap. Push firmly on ensure the tubing is
fully seated. Now push the hubcap and excess airline back into the axle spindle until the flange of
the hubcap is flush with the hub. As the tubing is being pushed back into the axle make sure it
doesn’t kink or bend.
• Align hubcap gasket with bolt holes on hubcap and install bolts. Install all bolts and snug down
until hubcap is seated against the hub. When all bolts are snug use a torque wrench to finish
tightening bolts to correct specification. Tighten bolts using a star pattern as shown in figure 16.
Torque bolts to 12-16 ft lbs. See Figure 15 and 17
Figure 15
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• Pull on the air line coming out of the axle until you feel it get tight (gently). Now push the pass
through fitting body down the air line and tighten it into the axle.
• Next push the rubber o-ring and the pass-through cap down on the tubing to the fitting.
• Before you tighten the pass through cap, push 4-5” of air line back into the axle, making sure not
to kink the air line. This will allow enough slack in the air line should you need to remove the Aeris
hubcap later.
• Tighten the pass through cap on the fitting. Do not over tighten.
• Using a tubing cutter, cut air line coming out of the closed pass through fitting on the axle 5” past
the center of the axle vent hole. You want to make sure you have enough air line to attach to your
tee fittings. See Figure 16
Figure 16
• Repeat same procedures on remaining ends of all spindles. Make sure when feeding air line
tubing into axle it heads towards the correct spindle end.
! IMPORTANT: Make sure to leave some slack in end of line when cutting for the hubcap airline fitting.
If hubcap needs to be removed you will need enough slack to unbolt the hubcap and be able to
remove the airline from the air fitting.
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Figure 17
• Depending on your hubcap type, Remove plug on hubcap and fill with oil to appropriate levels for
safe operation. Allow oil levels to stabilize and add oil until at correct levels for each hubcap.
! IMPORTANT: Make sure oil levels in each hubcap are at the recommended levels for safe operation
before using the trailer. Fill and allow oil to settle then check oil levels again. Add as needed to reach
the recommended levels.
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Control Box Installation
• Install control box mounting bracket with hardware provided. Mounting bracket can be mounted
flush against the back of bracket, flush against top of bracket to a cross member using top
mounting holes or welded to the frame. If welding, weld the bracket to the frame before attaching
the control box to the bracket. Choose to best option for your application and a location that
protects the control box from rocks, debris, etc as much as possible. If trailer has a slider frame
make sure bracket is mounted on cross member inside the slider frame box.
• Once mounting bracket is in place, install the control box to the bracket using hardware provided.
• Mount the control box with the door facing the backend of the trailer if possible. This will help
protect it from debris from road hitting it. If this is not possible mount the control box in a location
that allows access to the door, but is as free from as many hazards as possible. Do not mount
control box near tires. Control box should be mounted as high under the trailer as possible to
keep debris from the road from hitting it and water from getting inside box if trailer is backed into
loading dock that may be holding water. See Figure 18, 19
Figure 18
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• The control box has several mounting options. In all mounting options the 5/16” sealing washer,
lock nuts and flat washers must be used. The sealing washer is always on the inside of the box.
1. Attach the box (without the bracket) directly to a cross member or frame section using the
three 5/16” mounting holes in the bottom of the box. Be sure to leave room at the top for the
door to open up.
2. Use the mounting bracket provided with the Aeris system. The bracket can be mounted using
the holes on the side of the bracket or the holes in the top flange. The control box can then be
bolted to either side of the bracket (holes are symmetrical).
3. The mounting bracket can be welded to the trailer is desired, but the frame must have
clearance holes of the 5/16” mounting hardware (nut and flat washer) on the outside of the
box. The box must be removed from the bracket before welding and the welded area must
have some anti-corrosion treatment such as cold-zinc paint.
Figure 19
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Connecting air lines to control box
• After the hubcap is tightened down, push the rubber grommet on the air line down against the
body of the fitting and tighten the nut. Take the tubing from each spindle end and insert them into
the air line tee fitting over the center of the axle. It may be necessary to trim off excess tubing
going to the center of the axle. Repeat this step on all axles.
• Insert end of tubing into tee fitting on rear axle and run tubing to the front axle tee fitting and insert
into front axle tee fitting. Make sure to leave enough airline tubing from rear axle to the front axle
for axles that move Independent of each other to distribute load weight. Use tie-wraps to attach
tubing to stationary areas to keep tubing from dragging or getting hooked on anything while truck
is moving.
• On the front axle you will need to insert another tee fitting into the airline to connect the air supply
to outlet side on the control box. All airlines connected to the hubcap from each axle will be
hooked up to the outlet side of the control box mounted under the trailer. See Figure 20, 21 and
22
• Recommended to route and tie wrap airlines coming off the axles to existing wiring or tubing going
towards the location where the control box is mounted making sure airlines won’t be rubbing
against any sharp edges that may damage airlines.
• Center vent lines should be tied up under trailer where duck bill vent is vertical and where duck bill
won’t risk being under water if trailer is parked in a loading bay that may hold water. Make sure to
tie wrap center vent line to the trailer in an area that isn’t a moving component which could risk it
being pulled on. Vent line may be wrapped around axle if needed, just make sure duck bill is
facing vertically and then tie wrap vent line to fitting coming of the axle to hold it in place.
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Figure 20
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Figure 21
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Figure 22
Air Lines to Compressed Air Tank
! IMPORTANT: Open petcock valve on compressed air tank to release air pressure from
tank. Once compressed air is drained from the tank, close the petcock valve.
• Remove large 3/8” Plug from side of compressed air tank.
• Install the 3/8” NPT-M x 1/4” NPT-F bushing.
• Install the 1/4” nipple.
• Install “Inlet” side of the Pressure Protection Valve on nipple.
• Install the 90° swivel elbow 1/4" NPT-M X 1/4” tube/DOT fitting to “outlet” side of PPV.
• Run a piece of 1/4” tubing from the 90° swivel elbow to the “Inlet” side of the control box fitting.
• Make sure the mini ball valve on the “inlet” side of the control box is in the open position. See
Figure 23
Aeris Installation, Service and Troubleshooting Manual
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Figure 23
Item Description
1. Air tank Trailer Air Tank
2. Outlet Air Supply of Control Box Attach air lines from Aeris hubcap to “Outlet” side of control box
3. Inlet Air Supply of Control Box Attach air lines from PPV to “Inlet” side of control box
4. Pressure Protection Valve Required; 70 psi minimum closing pressure
5. Air Supply From Tractor Air supply hooked to air tank coming from the tractor compressor
6. Aeris Hubcap Axle Air lines Air line from Aeris hubcap axle air lines hooked to “Outlet” on control box
7. 1/4" Airline “Tee” Fittings 1/4" tube tee air line fittings to hook air lines from axles to air tank
8. Control Box Air lines and electrical wiring run to control box for Aeris system
9. Mini Ball Valve Air shut on/off valve. Must be in ”Open” position for Aeris system to work
Aeris Installation, Service and Troubleshooting Manual
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Tire Hose Installation
• Attach air hoses to the hubcap and the inner and outer valve stems. The hose with the 180° fitting
attaches to the outer valve stem. Turn the valve stem swivel nut on the fitting until the rubber
gasket just makes contact with the valve stem, then turn the nut 1/2 turn more to ensure proper
sealing. Now push the hubcap end of the tubing into the brass hose adapter fitting and turn the
nut until the fitting is snug. For final tightening, turn the check port stem and the nut at the same
time using only your fingers. Do not use any type of valve stem extensions. See Figure 24 and
26
• If installing on Super-Single wheel only one hose is required. See Figure 25
Dual tire hose to hubcap connection Super single tire hose to hubcap connection
Figure 2
4
Figure 2
5
! IMPORTANT: Make sure the hose(s) are not touching the tire rim. Contact between the hose and
the rim could damage the rim.
! IMPORTANT: Make sure the tire hose(s) are not stretched so tightly that it puts a strain on the valve
stem or the hubcap fittings. Clock wheels if hoses are not aligned with the valve stems.
Aeris Installation, Service and Troubleshooting Manual
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Figure 26
Light Kit and Wiring Installation
• Once the control box is mounted and the air lines are connected to the controller, the electrical
wiring and light kit can be installed. Improper wiring or operation of Aeris system can lead to the
driver not being aware the tire inflation system is not working correctly.
• This section gives the basic instructions on wiring the Aeris system and routing the electrical
wiring from the power source to the control box and light. Hardware kit is shown below with items
needed to install wiring and light. See Figure 27
Aeris Installation, Service and Troubleshooting Manual
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Figure 27
Item Qty Description
1. 1 - Wire Extension for light Used to connect light to light and 7 pin power box.
2. 7 - 10 X 3/4” Self Tap screw Used to attach light and P-clamps to trailer
3. 5 - P-Clamps Used to clamp down wire from light to trailer and to 7 pin power box
4. 3 - Wire Ring Terminal Connectors for end of wires to 7 pin power box.
5. 3 - Wire Female Disconnect Used to connect white, yellow, and brown wire to Aeris controller box.
6. 1 - Wire Butt Splice Used to connect light black wire to yellow wire from controller box
7. 1 - Light Pigtail Used to connect light to wire extension to 7 pin power box.
8. 1 - Light Aeris signal indicator
9. 25 - 6” Tie-wraps Used to secure wiring and airlines to trailer components.
10. 25 – 11” Tie-wraps Used to secure wiring and airlines to trailer components.
• Run the 3 wire cable down through the front of the trailer in conduit or space provided by the trailer
manufacturer. Make sure the cable stays inside the conduit or track between the tractor and the
trailer. Failure to do so may end up causing the wire to be damaged. See Figure 30
• Make sure to route the 3 wire cable under the trailer through the same holes that the brake airlines
and other electrical lines are running through. Make sure to secure the cable every 15 -20 inches
using the tie-wraps provided. Any excess cable that is not being used needs to be cut or bundled
and tie-wrapped to existing cable routings under the trailer. See Figure 28
Aeris Installation, Service and Troubleshooting Manual
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! IMPORTANT: Make sure to run the 3 wire cable along the same path the airline from the
brakes is routed. This will insure that you have enough slack in the electrical line to keep it
from be damaged by any moving parts on trailer. See Figure 29
Figure 2
8
Figure 2
9
! IMPORTANT: Do not allow 3 wire cable to rub against a sharp edge of a hole or straight edge
of a structural cross member as cable is being routed through the trailer. Use tie-wraps to
secure to existing airlines or electrical lines.
Figure 30
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• Once wire cable is pulled to the mounted controller box at the back of the trailer cut the cable.
Make sure to leave enough wire to have about 12” of wire inside the control box.
• Pull wire cable into the bottom of the control box through the cable glade. Once wire is inside the
box, tighten the nut to seal up around the cable. Tightening the cable gland will
prevent water from entering the box and helps keep the cable from being pulled on which could
lead to damaging the board inside the control box.
• Next strip the wire jacket from around the 3 wires back about 4” using a jacket stripping tool.
Make sure not to cut insulation around 3 wires inside jacket.
• Next strip 1/4” of insulation from the white, brown and yellow wires.
• Crimp the female wire disconnect (spade) terminals to the white, brown and yellow wires using a
crimping tool.
• Now connect the yellow wire to the “Light” terminal on the board, the brown wire to the “Power”
terminal on the board and the white wire to the “Ground” terminal on the board.
• Make sure to leave a loop at the bottom of the wires on the bottom of the control box. This keeps
water from running down the cable to the electrical board inside the control box. See Figure 31
• Close box cover and snap lid clamps.
Figure 31
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• Take the light and using the pigtail provided plug the pigtail into the 2 holes on the back of the
light. Plug the square flat ends into the light. Make sure connectors snap in place fully.
• Now on the other end of the pigtail, remove the 2 plugs in the ends of the connectors and plug in
the wire extension. Make sure connectors snap in place fully.
• Mount light in front corner of or side of trailer. Mount light in location where driver can see it in
driver’s side view mirror.
• Mount indicator light to trailer using the self tapping screw provided. Make sure to tuck wires
inside back of light and where wires come out of slots provided to keep from pinching wire when
mounted.
• Secure wire to trailer using p-clamps. Make sure wiring is not hanging down to catch on anything.
! IMPORTANT: Make sure that as you are installing the p-clamps you run the wire with a drip
loop in the bottom of cable below the 7 pin connector box. This keeps water from running
down the cable from the indicator light into the electrical box. See Figure 33
• Remove the cover to the trailer 7 pin connector box. See Figure 32
• Route the wire from the light into the 7 pin connector box. Route enough wire into the box to
have about 8” of wire sticking out and cut off excess wire. Strip about 5” of the wire jacket from
the wire using a jacket stripping tool. Make sure not to cut jacket so deep you cut into the
insulation on the wires.
• Strip off 1/4" of insulation from the black and white wire.
• Route end of the 3 conductor wire into the 7 pin connector box. Strip the wire jacket from around
the wires back about 6” using a jacket stripping tool. Make sure not to cut jacket so deep you cut
into the insulation on the wires.
• Next strip 1/4” of insulation from the white, brown and yellow wires.
• Take a ring terminal and crimp on the end of the white wire from the light and crimp a ring terminal
on the white wire going to the control box. Both white wires coming to the 7 pin connector box
should have a ring terminal crimped to them. Use a terminal crimping tool.
• Crimp ring terminal to the brown wire.
• Crimp butt splice to the Black wire from the light and the yellow wire from the 3 wire cable going to
the control box.
• Remove the nut from (Pin 1 biggest pin) on the 7 pin connector terminal and place the white wire
from the 3 wire cable on the post. Replace nut and tighten down.
• Remove the nut from (Pin 7) on the 7 pin connector and connect the brown wire from the 3 wire
cable to the post and the white wire from the light and tighten down the nut. This will be the center
pin and will carry the power on systems that support ABS.
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Figure 32
• Next tuck all the wires inside the 7 pin terminal box and install the cover back on the box. Make
sure you don’t trap any wires between the cover and the box that could cause the wire to short.
• Use tie wraps to attach 3 wire cable and wire cable from the light indicator to the airlines leading
out of the 7 pin connector box. See Figure 33
! IMPORTANT: Make sure you leave enough slack in the wires in the connector box to be able
to remove the cover and work on the wiring without pulling any of the wiring lose from
connectors when removing the cover of the box.
Aeris Installation, Service and Troubleshooting Manual
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Figure 33
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Decal Location
• Place decals on front of trailer by the indicator light and on the inside and outside of the control
box cover. See Figure 34
.
Figure 34
Label Location
Contents
Type
Purpose
Driver warning lamp area Logo, what the warning lamp
indicates, STEMCO contact
info and any applicable IP (This
system protected by patent
numbers…other patents
pending?)
Exterior grade, subject to
pressure washing, grease,
road chemicals. Needs to
adhere to a painted aluminum
or steel surface.
Branding, instructional and IP
communication
Aeris Logo
Control box front cover
(exterior)
Aeris logo, what this is (ATIS),
IP info (same as with DWL
label above)
Exterior grade, subject to
pressure washing, grease and
road chemicals. Needs to
adhere to a clean fiberglass
or plastic surface.
Branding, IP communication
Control box diagram
front cover (interior) Control box diagram and part
number, instructions and
STEMCO contact information.
Interior grade, black and
white, needs to adhere to
clean fiberglass or plastic
surface
Instructional and contact info
for reorder or troubleshooting.
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System Installation Check
• After the Aeris system is completely installed, but before the trailer is put back into service, all air
system connections need to be checked for leaks. Apply a soapy/water solution to all air
connections. If bubbles appear at any fitting or air connection, check connection to verify it is tight.
Follow Instructions Below:
Make sure the petcock valve on the trailer air tank is closed.
Fill the trailer air system and set all tire pressures just below the target pressures.
Ensure the mini ball valve on the controller box is in the open position.
Verify the trailer is connected to 12-volt power source.
Verify the “Red” light on the circuit board in the control box is blinking. If after applying 12-
volts you don’t see the light blinking, disconnect the 12-volt power source and check all wire
terminal connections and connections to the 7 pin connector box correct.
Indicator light on trailer should come on and blink 3 times. If insufficient pressure exists in the
system, the light will blink in a pattern of 1-long and then 2 short blinks, if low flow exists the
light will stay on constantly and if high flow exists the light will blink constantly.
If the indicator light remains on and the system continues attempting to inflate one or more
tires to the proper pressure but can’t due to the inability to maintain adequate pressure, the
system has a leak and must be repaired.
Verify the oil level in each wheel end is at the correct level.
Aeris Installation, Service and Troubleshooting Manual
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Maintenance
Check Tire Pressure
• Although the Aeris tire inflation system is designed to detect and fill a tire that’s leaking during
vehicle operation, STEMCO recommends you inspect the tires for normal wear and damage at
regular intervals and check the tire pressure as follows.
• Remove the metal cap from the check port that is provided on each hose. See Figure 35
Figure 35
• Check pressure going to each tire using a pressure gauge.
• If the tire pressure is correct: Replace fill cap and hand tighten.
• If the tire pressure in not correct: Check the following:
• Verify that the shut off valve is in open position.
• Check all air connections with soapy water solution. If bubbles can be seen,
tighten fittings and check again with soapy water solution.
• If pressure is too high release some pressure from the tire and replace the fill cap.
• The Aeris system will automatically inflate the tire to correct setting.
• Each tire should be checked for correct air pressure 4 times per year.
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Regulator Setting
• It’s recommended that you check the regulator pressure 4 times a year to verify the
regulator is still set at the desired pressure setting.
• Open the cover to the control box.
• Remove the metal cap on the check port fitting on the regulator.
• Check the pressure with an accurate gauge, such as a master gauge.
• If the pressure is correct, replace metal cap and close the lid.
• If the pressure is above or below the desired setting, adjust the pressure using the
adjustment knob. See Figure 36.
• If the pressure is “low” pull up on the regulator’s knob to unlock. Turn the knob
clockwise to increase the pressure. Allow the pressure to stabilize then check the
pressure 2-3 times to verify correct pressure. If the pressure is correct, push the
knob back down to lock in place and replace the metal cap.
• If the pressure is “high” turn the knob counter-clockwise to decrease the pressure.
Allow the system to stabilize and check the pressure 2-3 times to verify correct
pressure. Continue to decrease or increase the regulator until the desired pressure
is achieved.
Figure 36
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CERTIFICATIONS (USA)
This unit complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference,
and (2) this device must accept any interference received, including interference that may cause undesired operation.
FCC ID: SRA-830
This equipment equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These
limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio
frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no
guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception,
which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
-- Reorient or relocate the receiving antenna.
-- Increase the separation between the equipment and receiver.
-- Connect the equipment into an outlet on a circuit different from that to which the
receiver is connected.
-- Consult the dealer or an experienced radio/TV technician for help.
Note: The manufacturer is not responsible for any radio or TV interference caused by unauthorized modifications to this equipment. Such modifications could void
the user’s authority to operate the equipment.
The antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in
conjunction with any other antenna or transmitter. Users and installers must be provided with antenna installation instructions and transmitter operating conditions for
satisfying RF exposure compliance.
CERTIFICATIONS (Canada)
This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the
following two conditions: (1) this device may not cause interference, and (2) this device must accept any
interference, including interference that may cause undesired operation of the device.
Ce dispositif est conforme norme Industrie Canada RSS standard exempts de licence(s). Son utilisation est
soumise à Les deux conditions suivantes: (1) cet appareil ne peut pas provoquer d ’interférences et (2) cet
appareil doit accepter toute interférence, y compris les interférences qui peuvent un mauvais fonctionnement
du dispositif.
This product meets the applicable Industry Canada technical specifications/Le présent materiel est conforme
aux specifications techniques applicables d’Industrie Canada.
IC: 7413A-830
Stemco-USA Stemco-Canada
P.O. Box 1989 5900 Ambler Drive, Units 4 & 5
Longview, TX 75606-1989 Mississauga, ON L4W 2N3
(903) 758-9981 (905) 206-9922
1-800-527-8492 877-232-9111
FAX: 1-800-874-4297 FAX: 877-244-4555