GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Block the wheels.
  2. Drain all air reservoirs. Refer to Air Brake Reservoir Draining.

  3. Object Number: 201804  Size: SH
  4. Mark the position of the air brake automatic slack adjuster to the camshaft by drawing a straight line on both parts.

  5. Object Number: 201846  Size: SH
  6. Remove the front air brake chamber clevis pin retainers.
  7. Remove the front air brake chamber clevis pins.

  8. Object Number: 201809  Size: SH
  9. Remove the front air brake chamber clevis pin retainers.
  10. Remove the front air brake chamber clevis pins.

  11. Object Number: 201765  Size: SH
  12. Fully release the air brake automatic slack adjuster.
  13. Disengage the pawl with a screwdriver.
  14. Turn the air brake automatic slack adjuster adjusting nut until the air brake automatic slack adjuster is free from the air brake chamber clevis.
  15. Release the pawl so that the pawl snaps into engagement.

  16. Object Number: 209228  Size: SH
  17. Loosen the jam nut.
  18. Remove the air brake chamber clevis and the jam nut.
  19. Inspect the air brake chamber pushrod for damage. Overhaul or replace the service brake chamber assembly if damaged.

Installation Procedure


    Object Number: 209228  Size: SH
  1. Loosely assemble the jam nut and the air brake chamber clevis to the air brake chamber pushrod.
  2. Adjust the air brake chamber clevis by turning the air brake chamber clevis clockwise in order to decrease the distance and counterclockwise in order to increase the distance.

  3. Object Number: 1522502  Size: SH
  4. Adjust the front air brake chamber clevis to 69.9 mm (2.75 in) from the mounting surface of the air brake chamber to the center of the air brake chamber clevis pin mounting hole.
  5. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 209228  Size: SH
  6. Install the front air brake chamber clevis jam nut.
  7. • Type 16 air brake chamber

    Tighten
    Tighten the front air brake chamber clevis jam nut (type 16 air brake chamber) to 37 N·m (27 lb ft).

    • Type 20 and Type 24 brake chamber

    Tighten
    Tighten the front air brake chamber clevis jam nut (Type 20 and Type 24 brake chamber) to 61 N·m (45 lb ft).


    Object Number: 201765  Size: SH
  8. Fully release the air brake automatic slack adjuster.
  9. Disengage the pawl with a screwdriver.
  10. Turn the air brake automatic slack adjuster adjusting nut until the air brake automatic slack adjuster arm is properly aligned with the holes in the air brake chamber clevis.
  11. Release the pawl so that the pawl snaps into engagement.

  12. Object Number: 201809  Size: SH
  13. Install the air brake chamber clevis pins.
  14. Install the new air brake chamber clevis pin retainers.
  15. Adjust the brakes. Refer to Air Drum Brake Adjustment.
  16. Start the engine.
  17. Charge the system to the air compressor governor valve cut-out point.
  18. Stop the engine.
  19. Check for proper brake operation.
  20. Set the parking brake.
  21. Remove the wheel blocks.