GM Service Manual Online
For 1990-2009 cars only

Disassembly Procedure


    Object Number: 171484  Size: SH

    Caution: Keep fingers away from rear brake shoe springs to prevent fingers from being pinched between spring and shoe web or spring and backing plate.

    Notice: Do not pry against the splash shield or backing plate in attempt to free the drum. This will bend the splash shield or backing plate. A bent backing plate may cause brake chatter and/or pulsation.

    Notice: Do not over stretch the adjuster spring. Damage can occur if the spring is over stretched.

  1. Remove the wheel cylinder. Refer to Wheel Cylinder Replacement .
  2. Remove the boots (4).
  3. Remove the following components:
  4. • The pistons (3)
    • The seals (2)
  5. Remove the spring (5).
  6. Remove the bleeder valve (6).
  7. Inspect the cylinder bore (1) and the pistons (3) for the following conditions:
  8. • Scoring
    • Gouges
    • Corrosion
    • Wear
  9. Use a crocus cloth in order to polish out light corrosion.
  10. Replace the wheel cylinder (1) if the cylinder bore does not clean up with a crocus cloth.
  11. Clean all of the components in denatured alcohol.
  12. Dry all of the components with nonlubricated, compressed air.
  13. Lubricate the new seals with clean brake fluid.

Assemble


    Object Number: 171484  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.

  1. Install the bleeder valve (6).
  2. Tighten
    Tighten the bleeder valve (6) to 7 N·m (62 lb. in.).

  3. Install the spring (5).
  4. Install the following components:
  5. • The seal (2)
    • The pistons (3)
    • The boots (4)
  6. Install the wheel cylinder. Refer to Wheel Cylinder Replacement .