GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C-Series Medium Duty Truck B7 🢒 Brakes 🢒 Air Drums 🢒 Rear Air Brake Chamber Overhaul

Disassembly Procedure

    Object Number: 201678 Size: SH
  1. The spring brake chamber identification information is located on the adapter housing. The emergency side of the spring brake chamber uses a crimped safety seal and is not serviceable.

    2. Object Number: 201679 Size: LH
  2. Mark the adapter (10) and the service housing (5) in relation to the clamp ring assembly (3).
  3. Remove the air brake chamber clevis and the nut (2).

    4. Object Number: 201669 Size: SH
  4. Pull out the pushrod and use locking-type pliers to clamp the pushrod.

    5. Object Number: 201682 Size: SH
  5. Remove the nuts and the bolts.
  6. Remove the clamp ring assembly.

    7. Object Number: 201679 Size: LH
  7. Remove the service housing (5) from the adapter (6).

    8. Object Number: 201669 Size: SH
  8. Release the locking-type pliers from the pushrod.

    9. Object Number: 201674 Size: SH
  9. Remove the pushrod.

    10. Object Number: 201676 Size: SH
  10. Remove the return spring.

    11. Object Number: 201683 Size: SH
  11. Remove the diaphragm from the adapter.

    12. Object Number: 201679 Size: LH

    Important: Replace all worn and/or damaged parts.

  12. Inspect the inside of the service housing (5) for corrosion.

    13. Replace the service housing (5) if corrosion is found.

  13. Inspect the adapter (10) wall and the lip.
  14. Inspect the return spring (6).
  15. Inspect the pushrod (7).
  16. Inspect the clamp ring assembly (3).

Assembly Procedure

    Important: Compress the return spring and clamp the pushrod in place with locking-type pliers.


    Object Number: 201676 Size: SH
  1. Install the return spring into the service housing.

    2. Object Number: 201674 Size: SH
  2. Install the pushrod into the service housing.

    3. Object Number: 201683 Size: SH
  3. Install the diaphragm into the adapter.

    4. Object Number: 201679 Size: LH
  4. Install the service housing (5) onto the adapter (10).

    5. Object Number: 201682 Size: SH

    Important: Align the marks made during disassembly.

  5. Install the clamp ring assembly.

    6. 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.

  6. Install the bolts and the nuts.

    7. Tighten
    Tighten the nuts to 34 N·m (25 lb ft).

  7. Inspect the clamp assembly for the proper seating around the adapter and the service housing lip.

    8. Object Number: 201669 Size: SH
  8. Release the locking-type pliers.

    9. Object Number: 201679 Size: LH
  9. Loosely fit the nut and the spring brake chamber clevis to the pushrod.
  10. Install the nut (2) and the air brake chamber clevis to the pushrod (7).