GM Service Manual Online
For 1990-2009 cars only

This section covers the brake parts located at the wheels. For information on other air brake system components refer to Air Brakes or Air Compressor Brakes.

The air foundation brake assembly consists of the following components:

    • The air brake chamber
    • The air brake automatic slack adjuster
    • The brake assembly
    • The brake drum

Some models have the brake drum fastened outboard of the hub by the wheel studs and the nuts. Refer to Front and Rear Brake Drums (Outboard Mounted) . An outboard-mounted brake drum can be removed after removing the tire and the wheel assembly. The hub and the wheel bearings do not have to be removed.

Some models have the drum fastened inboard directly to the hub. Refer to Front and Rear Brake Drums (Inboard Mounted) or Front and Rear Brake Drums (Inboard Mounted) . In order to remove an inboard-mounted drum you must first remove the hub and the wheel bearings. The drum can then be separated.

The Eaton® air brake automatic slack adjuster is to be serviced by replacement only.

For unit repair information on the Rockwell air brake automatic slack adjuster contract the Rockwell Field Support Center at 1-800-535-5560.