How to Change the Rear Brake Cylinder on a 2001 Chevy Lumina

The wheel cylinder on a 2001 Chevy Lumina applies pressure to the brake shoes when the brake pedal is pressed. When a wheel cylinder is bad, fluid will begin to leak from the pistons that push the brake shoes when the brake is being used. To determine which wheel cylinder needs to be replaced, look for fluid leaking from behind either or both of the rear wheels. Replacing a wheel cylinder will require bleeding of the brake line it is attached to; you will need someone to help you complete this process properly.

Instructions

Break loose the lug nuts on the wheel to be serviced. Lift the rear end of the vehicle with the floor jack. Place the jack stands under the rear vehicle frame rails and carefully lower the vehicle until it rests securely on the jack stands.

Finish removing the lug nuts with the lug wrench. Remove the wheel from the vehicle. Remove the drum from the drum brake assembly by griping it firmly with both hands and pulling it away from the rear brake assembly. Place the drain pan under the drum brake assembly.

Disconnect the brake shoes from the brake assembly by pushing on the shoe retaining springs with the drum brake spring tool and turning to release the retainer and spring. You can leave the shoe return spring connected because the brake shoes only need to be moved out of the way to get to the wheel cylinder.

Disconnect the brake line from the wheel cylinder with the line wrench set. Remove the two retaining nuts from the wheel cylinder with the socket and ratchet set. Gently pull the wheel cylinder toward the outside of the vehicle until it is free from the drum brake assembly. Place the wheel cylinder into the drain pan to drain.

Slide the new wheel cylinder into place by pushing the wheel cylinder studs through the mounting holes on the backing plate. Secure it to the backing plate with the socket and ratchet set. Install the brake line into the new wheel cylinder and tighten it down with the line wrench set. Install the wheel cylinder bleeder screw into the wheel cylinder bleeder hole, which is directly above the brake line fitting, and lightly tighten it with the wrench set.

Reattach the brake shoes to the drum brake assembly by using the drum break spring tool to install the springs and retainers for both brake shoes. Remove the brake reservoir cap and fill to the top with brake fluid. Instruct your helper to sit in the driver's seat and start the vehicle. Ask him to pump the break until a firm pedal is achieved, then maintain pressure on the pedal.

Loosen the bleeder screw on the wheel cylinder until fluid and air begin to run from the bleeder valve. Instruct your helper to maintain pressure on the pedal as it travels to the floor, then to hold the pedal to the floor. Tighten the bleeder screw, then instruct your helper to pump the brake again until a firm pedal is achieved. Loosen the bleeder screw again and wait for the pedal to travel to the floor. Tighten the bleeder screw. Repeat until only brake fluid flows from the bleeder valve.

When all air is out of the brake line, instruct your helper to pump the brake until a firm pedal is achieved and then shut off the vehicle. Place the drum back onto the drum brake assembly. Place the wheel back onto the vehicle and hand-tighten all lug nuts.

Lift the vehicle off of the jack stands with the floor jack. Remove the jack stands from under the vehicle and slowly lower the vehicle to the ground. Tighten the lug nuts with the lug wrench. Torque the lug nuts to the manufacturer's recommended torque with the torque wrench. Add brake fluid to the brake fluid reservoir until full and replace the cap.