Tools Required

J 26267 Piston Seal Installer

1. Remove the front brake caliper from the vehicle. Refer to Brake Caliper Replacement .
2. Remove the brake caliper piston from the caliper bore by directing low pressure compressed air into the caliper bore through the fluid inlet hole.



3. Using a small wooden or plastic tool, remove the caliper piston seal (2) from the seal counterbore in the caliper (1) and discard the boot seal.
4. Using a small wooden or plastic tool, remove the piston seal (4) from the caliper bore and discard the piston seal.
5. Remove the bleeder valve (5) and cap (6) from the caliper (1).

Important: Do not use abrasives to clean the brake caliper piston.

6. Clean the brake caliper piston bore and seal counterbore, and the caliper piston with denatured alcohol, or equivalent.
7. Dry the caliper piston bore and counterbore, and the piston with non-lubricated, filtered air.
8. Inspect the caliper bore for the following conditions:

•

Cracks

•

Scoring

•

Pitting

•	Excess rust

•	Excess corrosion

9. If any of the above conditions are present in the caliper bore, replace the caliper assembly.
10. If light rust or light corrosion are present in the caliper bore, attempt to remove the imperfection with a fine emery paper. If the imperfection cannot be removed, replace the caliper assembly.
11. Inspect the caliper piston for cracks, scoring, and/or damage to the finished surface area. Replace the caliper piston if any of these conditions exist.

1. Lubricate the new piston seal with Delco Supreme 11® GM P/N 12377967, or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
2. Install the lubricated, new piston seal into the caliper bore.



3. Install the piston and the boot into the caliper bore using .
4. Push the piston to the bottom of the bore.
5. Install the new piston dust boot seal over the piston.



6. Install the boot into the caliper housing bore using the J 26267 .




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.

7. Install the front brake caliper bleeder valve.

Tighten
Tighten the valve to 13 N·m (115 lb in).

8. Install the front brake caliper to the vehicle. Refer to Brake Caliper Replacement .