BENDIX TCH-002-011 User Manual

Technical Bulletin

Bulletin No: TCH-002-011 Effective Date: 9/15/2008 Cancels: N/A Page: 1 of 1

Subject: Air Disc Brake Chamber Identifi cation

Proper identifi cation is crucial to servicing Bendix® ADB22X™ air disc brake chambers. Air disc brake chambers
can be much smaller than typical drum brake chambers in similar vehicle applications. For example, a common
drum brake trailer application may utilize a T ype 30 service brake chamber where an air disc brake for the same
trailer application would require a smaller, Type 18 service brake chamber.

The external diameter of a brake chamber on a drum brake application is often utilized to determine the
relative size of brake chambers. However, the external diameter cannot be used for selecting service
replacement actuators or components for air disc brakes. In some air disc brake applications, even though the
external diameter of two brake chambers may be identical, the internal components may be different. It is only
the internal components creating the application specifi c, balance critical force output that designates these
brake chambers as, for example, a Type 18 or a Type 20.

To accurately identify the proper brake chamber for replacement in an air disc bake application, the brake
chamber part number and/or the actual type must fi rst be identifi ed. This information is permanently attached
to the chamber. The fi gure(s) below identify common locations for these permanent brake chamber markings.

With this information your authorized Bendix Distributor can properly identify the proper replacement component.
You can also contact 1-800-AIR-BRAKE (1-800-247-2725) for additional assistance.

Air Disc Brake
Service Chamber

Knorr-Bremse

Part Number

Bendix Part

Number

Type / Size

Air Disc Brake
Spring Brake
Chamber

Type / Size

Bendix Part

Number

© 2008 Bendix Commercial Vehicle Systems LLC 9/2008. All rights reserved. Printed in U.S.A.