Important: 

Caution: Do not place your fingers in front of the piston in order to catch or protect the piston while applying compressed air. This could result in serious injury.

1. Remove the brake caliper from the vehicle. Refer to Rear Brake Caliper Replacement .




Notice: Use clean cloths to pad interior of caliper housing during piston removal. Use just enough air to ease the pistons out of the bores. If the pistons are blown out, even with the padding provided, it may be damaged.

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. Remove the piston boot (2).
4. Remove the piston seal (1).



5. Remove the brake caliper bleed screw cap.
6. Remove the brake caliper bleed screw (1).
7. Inspect the brake caliper bore and piston seal groove for scoring and corrosion. If badly scored or corroded around the piston seal area, replace the brake caliper housing.



8. Inspect the brake caliper mounting bracket guide surfaces for corrosion and wear. Remove and replace the brake caliper mounting bracket if necessary.
9. Clean all the residue from the brake pad guiding surfaces on the brake caliper housing and the brake caliper mounting bracket.
10. Clean all the parts not included in the repair kit with denatured alcohol.
11. Dry the caliper piston bore and counterbore, and the piston with non-lubricated, filtered air.
12. Blow out all passages in the brake caliper housing and the brake caliper bleeder valve.
13. 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.
14. If cracks, scoring, pitting, excessive rust, and/or excessive corrosion are present in the caliper bore, replace the caliper assembly.

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.

1. Install the brake caliper bleed screw (1).

Tighten
Tighten the brake caliper bleed screw to 12 N·m (106 lb in).

2. Install the brake caliper bleed screw cap.



3. 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.
4. Install the new seal (1) into the brake caliper bore seal groove.
5. Make sure the seal is not twisted.
6. Lubricate the brake caliper bore and the piston with brake fluid.
7. Install the boot (2) and piston.

7.1.	Install the boot over the end of the piston so that the fold will face toward the brake caliper housing piston bore opening.

7.2.	Seat the boot into the brake caliper bore groove and slide the piston into the brake caliper bore.

7.3.	Push down the piston to the bottom of the brake caliper bore.

7.4.	Make sure the boot is properly seated into the piston groove and into the groove in the brake caliper bore.

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