GM 20876917
Brake Pads

Before working on rear disc brake pads (J56) check the brake master cylinder fluid level. If the fluid sits at midpoint between marks you can continue without fluid removal. When the fluid level is above midpoint drain it until it reaches midway position. Lift the vehicle and take out all parts from the wheel assembly so you can start work. Take off the lower Brake Pad guide pin and Brake Pad spring before removing the upper Brake Pad guide pin and brake pads. Insert the brake caliper pistons into their bores with a spreader tool when they are fully in position. Replace any guide pins that show damage or corrosion instead of trying to clean them. Rephrase the brake piston boot when it shows clear signs of damage. Force the Brake Pad guide pin into the brake caliper housing until it reaches its complete position. Use the Brake Pad spring and lower guide pin to pass through the brake caliper before sliding over its edge to ensure proper installation. Place the tire wheel back onto the vehicle. Depress the brake pedal with an engine turned off until it reaches 2/3rd of its total motion and let the pedal return slowly. Press and hold the brake pedal for 15 seconds then release it before repeating the action till the brake pedal response becomes solid and pistons pad placement is complete. Complete the brake system by adding fluid then using a special tool to prepare new brake pads and rotors.

Remove the upper brake caliper guide pin bolt and pivot the brake caliper forward.

Clean the threads with denatured alcohol and apply threadlocker GM P/N 12345493 to 2/3 of the threaded length.

Tighten to 27 N.m (20 lb ft) for JE5 or 65 N.m (48 lb ft) for J55.

Place the new upper and lower brake pad springs, install the inner and outer brake pads, and rotate the brake caliper into position.