BENDIX TCH-013-018 User Manual

Technical Bulletin

Bulletin No: TCH-013-018 Effective Date: 8/24/2009 Cancels: N/A Page: 1 of 3

Subject: Bendix

When installing valve components on a vehicle, including service replacement parts, the installer needs to carefully
follow the installation guidelines. Not following these guidelines can lead to damage of the valve and reduced
vehicle braking. Bendix Commercial Vehicle Systems LLC has identifi ed that some Bendix® AT- 3™ solenoid
valve bodies have become damaged and may result in leakage. Bendix recommends that the crimp area
of the AT-3™ valve be inspected and replace the valve if this area has been found to have become loose.
See Figure 1.

The Bendix® AT- 3™ solenoid valve is a specialized air brake valve which may be used for several functions,
depending on the specifi c vehicle needs. Most typically, the AT-3™ solenoid valve is used in the Bendix
automatic traction control and Bendix® ESP® stability systems. See Figure 2 for typical applications of the Bendix
AT-3™ solenoid valve. One or two of these valves may be installed on a vehicle.

Valve Body

Supply Port

®

AT-3™ Valve Leakage

Crimp Area

Mounting Holes

Delivery

Por t

Solenoid Body

Clamp From

Both Sides of

Mounting Hole

Flange

Permitted

Clamp

Location

Never Clamp

Using Solenoid

Body

Permitted

Clamp

Location

Electrical

Connector

Service /

Exhaust

Por t

®

ATC

FIGURE 1 - THE BENDIX® AT-3™ SOLENOID VALVE
To identify if the AT-3™ solenoid valve on your vehicle is damaged, perform the following inspection. Follow all

standard industry safety precautions, including, but not limited to, those included in this document.

1. Park the vehicle on a level surface and block the wheels and/or hold the vehicle by means other than the air
brakes.

2. Drain the air pressure from all vehicle reservoirs.

™

3. Locate the AT-3

4. With the valve mounted on the vehicle, grasp the solenoid body with your hand and attempt to rock it, checking
for looseness of the crimp area. If the solenoid body moves, or rocks, then the valve is damaged and should
be replaced. Replacement valves are available through any Bendix authorized parts distribution center. If a
replacement valve is needed, be sure to follow the installation guidelines included with the valve to prevent
damage to the replacement valve.

solenoid valve(s) on the vehicle. See Figure 2.

Continued ...

Bulletin No: TCH-013-018 Effective Date: 8/24/2009 Cancels: N/A Page: 2 of 3

Supply

Secondary

Primary

Subject: Bendix

ABS

Modulator

Foot Brake

Trailer Modulator Valve

ABS

Modulator

®

AT-3™ Valve Leakage

From Trailer

Control Valve

Piloted

SER

DEL

SUP

Relay Valve

Supply

Secondary

Valve

AT-3

Solenoid

Valve - Steer

Axle (ESP)

™

Quick

Release

Valve

Tractor

Protection

Primary

PRIMARY

Valve

Pressure

Reducing

Valve

Double

Check

Valve

SUP

DEL

EXH

AT-3™ Solenoid Valve

(HSA-Hill Start Aid)

™

Solenoid

AT-3

Valve - Drive Axle

(ATC / ESP)

SER

DEL

SUP

ABS

Modulator

Relay
Valve

ABS

Modulator

FIGURE 2 - EXAMPLE APPLICATIONS OF BENDIX® AT- 3™ SOLENOID VALVE; 6X4 TRACTOR WITH

TRACTION CONTROL, ELECTRONIC STABILITY AND HILL START AID

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.

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 (A TC), the A TC
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.