GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Block the wheels.
  2. Cage the rear air brake chambers. Refer to Caging the Rear Air Brake Chamber .
  3. Drain all air reservoirs. Refer to Draining Reservoirs in Air Brakes.
  4. Remove the retainer.

  5. Object Number: 201826  Size: SH
  6. Remove the clevis pin.
  7. Fully release the slack adjuster by turning the slack adjuster counterclockwise. Continue the operation until the slack adjuster arm is free from the clevis.

  8. Object Number: 207511  Size: SH
  9. Loosen the jam nut.
  10. Remove the clevis and the jam nut.
  11. Inspect the service brake chamber pushrod for damage.
  12. Overhaul or replace the service brake chamber if damaged.

Installation Procedure


    Object Number: 207511  Size: SH
  1. Loosely assemble the jam nut and the air brake chamber clevis to the service brake chamber pushrod.
  2. Adjust the clevis.
  3. Turn the air brake chamber clevis clockwise in order to decrease the distance and counterclockwise in order to increase the distance.


    Object Number: 201873  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  4. Measure the front air brake chamber clevis to 72.0 mm (2.83 in) from the mounting surface of the service brake chamber to the center of the air brake chamber clevis pin mounting hole.

  5. Object Number: 201877  Size: SH
  6. Measure the rear air brake chamber clevis to 68.5 mm (2.69 in) from the mounting surface of the spring brake chamber to the center of the air brake chamber clevis pin mounting hole.
  7. Tighten

        • Tighten the front air brake chamber clevis jam nut (type 16 service air brake chamber) to 45 N·m (33 lb ft).
        • Tighten the front air brake chamber clevis jam nut (types 20 and 24 service air brake chamber) to 78 N·m (57 lb ft).
        • Tighten the rear air brake chamber clevis jam nut to 77 N·m (56 lb ft).

    Object Number: 207511  Size: SH
  8. Rotate the adjusting hex of the slack adjuster clockwise.
  9. Continue the operation until the arm hole of the slack adjuster lines up with the clevis hole.


    Object Number: 201826  Size: SH
  10. Install the air brake chamber clevis pin.
  11. Install the air brake chamber clevis pin cotter pin.
  12. Adjust the brakes. Refer to Air Drum Brake Adjustment .
  13. Start the engine.
  14. Charge the system to the air compressor governor valve cut-out point.
  15. Stop the engine.
  16. Uncage the rear air brake chambers. Refer to Caging the Rear Air Brake Chamber .
  17. Check for the proper brake operation.
  18. Apply the parking brake.
  19. Remove the wheel blocks.