GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Optra 🢒 Brakes 🢒 Disc Brakes 🢒 Rear Brake Caliper Overhaul

Disassembly Procedure
  1. Remove the caliper. Refer to Rear Brake Caliper Replacement .
  2. Remove the guide pin bolts and the bracket.
  3. Pull out the pins and the rubber boots.
  4. Remove the rear brake pads. Refer to Rear Disc Brake Pads Replacement .

    5. Object Number: 1255727 Size: SH
  5. Insert a cloth into the caliper housing.

    6. Caution: Wear safety glasses when using compressed air in order to prevent eye injury.

    Caution: Do not place fingers in front of the caliper piston(s) in an attempt to catch or protect it when applying compressed air. The piston(s) can fly out with force and could result in serious bodily 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.

  6. Apply unlubricated compressed air at the hose inlet of the caliper in order to remove the piston from the caliper.

    7. Object Number: 1255731 Size: SH
  7. Remove the piston dust seal.
  8. Remove the inner seal from the bore. Avoid scratching the bore.

    9. Object Number: 1255732 Size: SH
  9. Remove the bleeder valve dust cap and the bleeder valve.

Inspection Procedure

    Object Number: 1255731 Size: SH
  1. Clean all parts in denatured alcohol or brake fluid. Dry the parts with unlubricated compressed air and blow out all passages in the housing and the bleeder valve.
  2. Inspect the bleeder valve.

    3. Important: Do not use a hone or any other procedure to remove material from the caliper bore or the piston.

  3. Inspect the piston and caliper for scoring, nicks, or corrosion. Replace components if necessary.

Assembly Procedure

    Object Number: 1255728 Size: SH
  1. Lubricate a new piston inner seal with brake fluid.
  2. Install the piston inner seal into the groove in the caliper bore.

    3. Object Number: 1255730 Size: SH
  3. Lubricate the piston dust seal with brake fluid.
  4. Install the piston dust seal in the groove.
  5. Lubricate the piston with brake fluid.
  6. Push the piston into the bore. Ensure the dust seal is seated in the piston groove and in the caliper.
  7. Coat the pins with Silicone Brake Lubricant, GM P/N 89021536, ACDelco P/N 89021537 (Canadian P/N 89021538), or equivalent, and install the boots.

    8. Notice: Refer to Fastener Notice in the Preface section.

  8. Install the bleeder valve and the dust cap.

    9. Tighten
    Tighten the caliper bleeder valve to 8 N·m (71 lb in).

  9. Install the rear brake pads. Refer to Rear Disc Brake Pads Replacement .
  10. Install the bracket and the guide pin bolts.

    11. Tighten
    Tighten the bolts to 27 N·m (20 lb ft).

  11. Install the caliper. Refer to Rear Brake Caliper Replacement .