How to Change the Rear Brakes on a Pontiac Grand Prixby ContributorUpdated November 07, 2017
Items you will need
Lug nut wrench
Heavy duty plastic container
Allen head, star head or 6-point socket wrench
Small bungee cord or wire hanger
Spanner wrench type caliper piston installer
New brake pads and shims
Piston spanner tool (not for Grand Prix RPO Z7U)
High temperature lubricant (not for Grand Prix RPO Z7U)
How to Change the Rear Brakes on a Pontiac Grand Prix. Brake pads are an important part of your Pontiac Grand Prix's braking system. They are the replaceable friction pads that pinch the brake disc or drum when the brakes are applied. You should replace the brake pads before they wear beyond a quarter inch or risk damaging your Grand Prix's brake discs. This procedure covers all Grand Prix models, including the RPO Z7Us.
Remove the old Brake Pads
Park your car on a level surface. If you have a stick shift car make sure the car is in gear. Place blocks in front of the front tires so the car does not move while you are working on it.
Open the hood of your car and locate the master cylinder. If necessary, remove brake fluid until the level in the container is less than half full. A turkey baster is a good tool for this. Put the brake fluid in the plastic container and dispose of it the way you dispose of motor oil.
Raise the rear end of your car with your car jack. Remove the rear tire or wheel assembly.
Remove the parking brake cable from the back of the caliper. Use the pliers to remove the cable clip (restraining clip). This step is done only for Grand Prix RPO Z7Us.
Hand-tighten two lug nuts to the studs to hold the disc rotor in place while you work on the caliper. Remove the bolt and washer holding the cable support bracket to the caliper. The cable support has the parking brake cable and brake hose attached to it. This step is not done for Grand Prix RPO Z7Us.
Use the socket wrench to remove the caliper guide pin bolts. Slide the caliper off of the disc rotor and hang it in the wheel well with a small bungee cord or wire hanger; Don't let the caliper hang from the brake hose.
Remove the brake pads and shims from the caliper. Throw away the shims.
Install the new Brake Pads
Use the spanner tool to rotate the piston clockwise all the way into the caliper. Make sure the notches on the piston are at the 6 and 12 o'clock positions. There is a boot (rubber seal) around the piston bore. Lift the seal's inner edge and press out any trapped air. Insert the brake pad clips into the caliper support.
Apply a thin coat of lubricant to the parts of the inner pad that come in contact with the caliper piston and mounting areas. As you install the brake pads in the caliper support, make sure the wear sensors are downward and at the leading edge of the rotor when the tire rotates. Push the brake pads into the support, holding the metal shoe edge against the spring end of the pad clips. This slightly bends the spring ends and lets the notches engage with the support. This step does not apply for the Grand Prix RPO Z7U.
Swing the caliper back into place over the brake pads and replace the mounting bolt. Reconnect the cable support bracket and tighten the bolt to 32-ft.lb. (43 Nm). Remove the lug nuts holding the rotor in place. For the Grand Prix RPO Z7U, Slide the caliper back into place on the disc rotor. Reconnect the parking brake cable. Insert and tighten the caliper mounting bolts to 44 foot lb. (60 Nm).
Replace the tire wheel assembly. Lower the car to the ground.
Pump the brake pedal a few times to seat the brake pads. Do this before trying to move your car.
Add fluid to the master cylinder container to replace any you removed before you removed the old brake pads.
Season the brake pads by making only gentle stops when you are driving for the first week after you install the new brake pads. Try not to do any hard stopping when you are seasoning the brakes.
The master cylinder is a metal cylinder located in front of the steering wheel on the metal firewall that separates the engine from the body of the car. On top of the cylinder there is a plastic container that holds brake fluid for the system. When you work on the brakes you adjust the level of fluid so that the container is less than half-full. Parking brakes are operated by a long, steel cable that runs between the handle in the cockpit and the rear wheels. The parking brake cable is the cable that runs from the caliper backing plate to the car body. The brake cable is very thick and rubber-coated. Be careful. The brake cable is easily confused with the brake hose, which is a steel tube connected to the car body with a short rubber hose. Use pliers to remove the parking brake cable. It is held in place with retaining clips. The caliper is the arc-shaped, cast iron piece attached to the brake rotor. It is usually on the upper-rear of the brake rotor. Caliper bolts are located on the back side of the caliper. Use penetrating oil to loosen the bolts if necessary.
Be careful using brake fluid. It is an eye irritant and is hazardous if swallowed. Always wash your hands thoroughly after you have been handling brake fluid. If brake fluid does get in your eyes, immediately use clear, running water to flush your eyes for 15 minutes. If your eyes are still irritated after you rinse them or if you swallow any brake fluid, get medical assistance immediately. Be careful when you are handling used brake parts. The dust and dirt on the brake parts may contain asbestos fibers that can be hazardous to your health if they are inhaled. When you clean brake parts, always use a damp cloth, not compressed air, wire brushes, scouring pads, or anything else that could move the dust and dirt particles around. Throw away any cleaning cloths that you use and swept up dirt and dust in a sealed, impermeable container. For more information, visit the library or go online to view the Environmental Protection Agency (EPA) and the Occupational Safety and Health Administration (OSHA) guidelines and procedures for handling or throwing away anything that might contain asbestos fibers.