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

1. Remove the rear brake caliper from the vehicle. Refer to Rear 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 piston dust boot 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 cracks, scoring, pitting, excessive rust, and/or excessive corrosion.
9. 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.
10. If cracks, scoring, pitting, excessive rust, and/or excessive corrosion are present in the caliper bore, replace the caliper assembly.
11. Inspect the caliper piston for cracks, scoring, and/or damage to the chrome plating. Replace the caliper piston if any of these conditions exist.

1. Lubricate the new piston seal with Delco Supreme 11® GM P/N 12377967 (Canadian P/N 992667) 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 caliper piston into the caliper bore.



4. Install the new piston dust boot seal over the piston.
5. Fully seat the dust boot seal into the caliper.
6. Install the bleeder valve and cap to the caliper and tighten the valve securely.
7. Install the rear brake caliper to the vehicle. Refer to Rear Brake Caliper Replacement .