GM Service Manual Online
For 1990-2009 cars only

Disassembly Procedure

Caution: Refer to Brake Dust Caution in the Preface section.

Caution: Refer to Brake Fluid Irritant Caution in the Preface section.

  1. Drain all the brake fluid from the caliper.

  2. Object Number: 399353  Size: SH
  3. Pad the interior of the caliper with clean shop towels.
  4. Caution: Do not place your fingers in front of the piston in order to catch or protect the piston while applying compressed air. This could result in serious injury.

    Notice: Use just enough air pressure to ease the piston out of the bore. You can damage a blown-out piston even with the padding.

  5. Remove the piston from the caliper bore.

  6. Object Number: 406916  Size: SH
  7. Remove the boot from the caliper bore. Do not scratch the housing bore.

  8. Object Number: 311224  Size: SH
  9. Remove the piston seal from the caliper bore. Do not use a metal tool.

  10. Object Number: 311142  Size: SH
  11. Remove the bleeder valve and bleeder valve cap from the caliper body.
  12. Remove the guide pins and guide pin sleeves from the anchor bracket.
  13. Clean the following components with denatured alcohol.
  14. • The bleeder valve
    • The caliper bore
    • The caliper passages
    • The piston
    • The lining contact area on the anchor bracket.
  15. Dry the parts and blow out the brake fluid passages. Use dry and filtered compressed air.
  16. Replace the piston or the caliper if any of the following conditions exist:
  17. • Scoring on the piston surface or in the caliper bore
    • Corrosion on the piston
    • Chrome plating damage on the piston
    • Corrosion in the caliper bore. Use crocus cloth in order to polish light corrosion from the caliper bore. Replace the caliper if the corrosion cannot be removed.
    • Pitting in the caliper bore

    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.

  18. Replace the bleeder valve cap.
  19. Tighten
    Tighten the bleeder valve to 12 N·m (110 lb in).

Assembly Procedure


    Object Number: 311242  Size: SH
  1. Lubricate the new piston seal, the caliper bore, and the piston with clean brake fluid.

  2. Object Number: 311224  Size: SH
  3. Install the piston seal. Make sure the piston seal is not twisted in the caliper bore groove.
  4. Install the boot into the caliper housing bore by hand.
  5. Install the piston in the caliper bore. Push the piston to the bottom of the bore by hand.

  6. Object Number: 147  Size: SH
  7. Install the boot on the piston.