GM 89047757
Brake Pads

Begin work on the rear disc Brake Pad replacement once you have evaluated the fluid level in the brake master cylinder reservoir. If the level sits midway between high and low marks no evacuation is necessary while lower fluid levels warrant adjustment to midway point. Before starting lift the vehicle off the ground and take off the wheel assembly with its tire. You can move the caliper past the brake rotor by compressing the caliper piston with a large c-clamp before taking out the clamp. Support the caliper with mechanic wire after loosening the lower brake pin bolt and holding the guide pin with a wrench. Move the caliper raised position to take out brake pads and retainers from their bracket. Test the brake caliper guide pin bolts and pins for any signs of damage and corrosion before replacing them. Also check the guide pin seals and piston boot for breakdown and replace them if needed. Press the piston fully towards the wheel side using a c-clamp over an old pad or wood block, then disconnect c-clamp to place Brake Pad retainers and new brake pads properly. Position the caliper over the pads into the bracket and clean both ends of the lower pin bolt along with its mounting holes while adding threadlocker gm p/n 12345493. After 10 minutes the brake caliper guide pin receives high-temperature silicone lube before installing the lower brake caliper pin bolt at 60 n.m (44 lb ft). Put the tire assembly back on the wheel and lower the vehicle. With the engine off press the Brake Pedal to two-thirds of its travel before lowering it slowly. Press the Brake Pedal several times until you reach total Brake Pedal firmness which allows the caliper pistons to settle correctly with brake pads. Complete the brake system by adding fluid to the master cylinder and do pad/slotted rotor burnishing work.

Inspect the brake caliper guide pins and replace if damaged or corroded, and check the brake caliper piston boot for damage, replacing if necessary.

Reinstall the tire and wheel assembly, lower the vehicle, and with the engine off, gradually apply the brake pedal to about two-thirds of its travel, then slowly release it.

Use a large C-clamp to compress the caliper pistons into the caliper bores.

Remove the C-clamp and loosen the lower brake caliper pin bolt while holding the guide pin with a wrench.

Inspect the fluid level in the brake master cylinder reservoir; if the level is midway between the maximum and minimum points, no fluid needs to be removed.

Wait 15 seconds and repeat until a firm brake pedal is achieved, which will properly seat the caliper pistons and brake pads.

Raise and support the vehicle, then remove the tire and wheel assembly.

Fill the brake master cylinder reservoir to the proper level and burnish the pads and rotors.

Raise and support the vehicle, then remove the tire and wheel assembly.

Install the brake pad retainer under the upper caliper pin assembly, rotate it down, and apply pressure downward on the lower end of the retainer.

Use the large C-clamp again to compress the caliper piston completely into the caliper bore, then remove the clamp and install the brake pad retainers and new brake pads, ensuring the wear sensor is positioned correctly.

Tighten it to 34 N.m (25 lb ft).

Install the lower caliper guide pin through the caliper and brake pads, seating it as before while ensuring the brake pad retainer is centered.

Apply threadlocker GM P/N 12345493 (Canadian P/N 10953488) to two-thirds of its length.