GM Service Manual Online
For 1990-2009 cars only

Disassembly Procedure


    Object Number: 1206813  Size: SH
  1. Using a small screw driver, remove piston boot ring (slowly pry up one end of boot ring) and piston boot from caliper.

  2. Object Number: 1206814  Size: SH

    Caution: To prevent bodily injury, make sure to keep fingers or other body parts away from piston during removal.

    Notice: Pad interior of caliper body to provide a protective cushion for piston when it exits the caliper. This will protect piston from surface damage caused from piston/caliper body contact.

  3. Remove piston from caliper body by applying low pressure, non-lubricated, compressed air into caliper inlet hose.

  4. Object Number: 1206756  Size: SH
  5. As an alternative, use SA91110NE (or equivalent) in the piston to rotate the piston counerclockwise, thereby threading the piston out of its bore.

  6. Object Number: 1206897  Size: SH
  7. Remove piston seal from groove in caliper body.
  8. Notice: To prevent damage to caliper body bore, use a small wooden or plastic (not metal) device to extract seal.

  9. Remove bleeder valve and bleeder valve cap from caliper body.

  10. Object Number: 1206911  Size: SH
  11. Only if replacing lever return spring:
  12. 6.1. Use screwdriver to disengage return spring from lever.
    6.2. Unhook spring from stopper pin.
  13. Clean all parts in clean denatured alcohol. Dry with non-lubricated, low pressure, compressed air. Make sure to blow out all passage in caliper body and bleeder valve.

  14. Object Number: 1206913  Size: SH
  15. Inspect piston for scoring, nicks, cracks, wear or corrosion. Replace piston if any damage is found.
  16. Inspect caliper body piston bore for scoring, nicks, wear or corrosion. Crocus cloth can be used to remove light corrosion. If more extensive damage is present, replace the caliper.
  17. Important: Do not hone caliper bore.

  18. Inspect seal groove in caliper bore for nicks or burrs. If present, replace caliper.

Assembly Procedure


    Object Number: 1206897  Size: SH
  1. Install bleeder vavle into caliper body assembly.
  2. Tighten
    Tighten to: 11 N·m (8 lb ft)

  3. Install bleeder valve cap.
  4. Important: Make sure seal is not twisted and that outer lip of seal faces out.

  5. Lubricate new piston seal with clean brake fluid and install into caliper seal groove.

  6. Object Number: 1206921  Size: SH
  7. Lubricate piston boot with clean brake fluid and install onto piston.
  8. Lubricate outside diameter of piston with clean brake fluid.
  9. Install piston into caliper body.
  10. 6.1. Start piston into bore by hand.
    6.2. Use SA91110NE (or equivalent) in the piston slots to rotate the piston clockwise, thereby threading the piston into its bore.
    6.3. Position piston indentation slots as shown.

    Object Number: 1206923  Size: SH
  11. Install boot ring.
  12. 7.1. Make sure that the outside edge of the piston boot is smoothly seated in counterbore of caliper body.
    7.2. Work boot ring into groove near open end of caliper bore utilizing care not to pinch piston boot between boot ring and caliper body.
    7.3. After installing boot ring, lift inner edge of piston boot to release any trapped air. The boot must lie flat, below the level of the piston face.

    Object Number: 1206911  Size: SH
  13. Install new lever return spring (if replaced).
  14. 8.1. Position spring with hook end around stopper pin.
    8.2. Pry other end of spring over lever.