GM Service Manual Online
For 1990-2009 cars only

Front Brake Caliper Overhaul Single Piston

Tools Required

J 26267 Piston Seal Installer

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

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

Disassembly Procedure


    Object Number: 141  Size: SH
  1. Drain all of the brake fluid from the caliper.
  2. Install a piece of wood or shop towels between the caliper and the piston.
  3. Cover the brake caliper with a shop rag.
  4. Caution: Refer to Eye Protection Caution in the Preface section.

    Caution: Refer to Safety Glasses and Compressed Air Caution in the Preface section.

  5. Apply only enough compressed air to the brake caliper to remove the piston.
  6. Remove the shop rag cover from the brake caliper.
  7. Remove the piece of wood or shop towels from the brake caliper.

  8. Object Number: 142  Size: SH
  9. Remove the boot from the front brake caliper.

  10. Object Number: 143  Size: SH

    Important: When removing the front brake caliper piston seal, use a non metallic tool.

  11. Remove the front brake caliper piston seal.

  12. Object Number: 145  Size: SH
  13. Remove the bleeder valve from the brake caliper body.
  14. Clean the following items with denatured alcohol.
  15. • The bleeder valve
    • The brake caliper body bore
    • The brake caliper piston

    Important: If the corrosion cannot be removed, replace the brake caliper housing and piston.

  16. Using a crocus cloth, clean the corrosion from the brake caliper bore.
  17. Dry the parts using non lubricated, filtered compressed air.
  18. Replace the brake caliper or the piston if any of the following conditions exist:
  19. • Scoring on the piston surface or in the caliper bore
    • Corrosion on the piston
    • Chrome plating damage on the piston
    • Pitting in the caliper bore

Assembly Procedure


    Object Number: 1079  Size: SH
  1. Lubricate the following parts with clean brake fluid.
  2. • The piston
    • The piston seal
    • The brake caliper bore

    Object Number: 399639  Size: SH

    Important: Ensure that the piston seal is not twisted in the brake caliper bore groove.

  3. Install the piston seal.

  4. Object Number: 147  Size: SH
  5. Install the boot on the piston.

  6. Object Number: 399639  Size: SH
  7. Install the piston in the caliper bore.

  8. Object Number: 177733  Size: SH
  9. Using J 26267 , install the front caliper piston boot. .

  10. Object Number: 145  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.

  11. Install the bleeder valve.
  12. Tighten
    Tighten the bleeder valve to 12 N·m (110 lb in).

Front Brake Caliper Overhaul Dual Piston

Tools Required

    • J 8092 Driver Handle
    • J 43885 Boot Seal Installer

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

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

Disassembly Procedure


    Object Number: 382726  Size: SH
  1. Drain all the brake fluid from the caliper.
  2. Install a piece of wood or shop towels between the piston and the inside of the brake caliper.
  3. Caution: Refer to Eye Protection Caution in the Preface section.

    Caution: Refer to Safety Glasses and Compressed Air Caution in the Preface section.

  4. Remove the pistons (2) from the caliper bores.
  5. Remove the boots (1) from the caliper bores. Do not scratch the caliper bores.
  6. Remove the piston seals (3) from the caliper bores. Do not use a metal tool.
  7. Remove the bleeder valve cap (4).
  8. Remove the bleeder valve (5) from the caliper housing (6).
  9. Clean the bleeder valve, the caliper bores, the caliper passages and the pistons with denatured alcohol. Dry the parts and blow out the brake fluid passages. Use dry and filtered compressed air.
  10. Replace the pistons or the caliper if any of the following conditions exist:
  11. • 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 a 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

Assembly Procedure


    Object Number: 382726  Size: SH
  1. Lubricate the new piston seals (3), the caliper bores, and the pistons (2) using clean brake fluid.
  2. Install the piston seals (3). Ensure that the piston seals are not twisted in the caliper bore grooves.
  3. Install the boot seals (1) on the pistons (2).
  4. Install the pistons in the caliper bores.
  5. 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 bleeder valve (5) in the caliper housing (6).
  7. Tighten
    Tighten the bleeder valve to 7 N·m (62 lb in).

  8. Install the bleeder valve cap (4).

  9. Object Number: 537191  Size: SH
  10. Install the boot seals into the caliper housing bores using the J 8092 and the J 43885 .