How to Replace ABS Rear Disk Brakes

Automotive braking is greatly enhanced when an anti-lock braking system is used. Known widely by the acronym ABS, the anti-lock braking system acts to keep the wheels from locking during braking, thus preventing skids and stopping the vehicle more quickly than conventional brakes. ABS consists of speed sensors at each wheel and a control module that monitors these sensors and controls the braking action. The rotational part of the speed sensors are normally embedded in the wheel hubs, and, because the disks and brake pads are actually separate from the hubs, there is no difference in disk brake replacement procedures for ABS and non-ABS disk brakes.

Instructions

1

Park the vehicle on a firm, level surface. Put automatic transmissions in the "Park" setting, and put manual transmissions in either first or reverse gear. Set the parking brake, and securely block the front wheels, to prevent accidental vehicle movement. Loosen the lug nuts about half a turn each, and jack the car. Support the vehicle, securely, on an axle stand. Completely remove the lug nuts, and pull off the wheel.

2

Remove the two caliper retaining bolts. Grasp the caliper, and rock it back and forth a few times, to spread the brake pads a bit. Lift the caliper off the disk. Hang the caliper out of the way, using a wire or bungee cord, taking care not to stretch or damage the flexible brake hose. The coil spring on the nearby suspension is often a good place to hang the caliper.

3

Slide the brake pads out of the caliper. If retaining clips are present, these can be pried off with a screw driver or pulled off with pliers. Take care not to damage clips during removal, so they can be reused.

4

Retract the piston back into the cylinder, by placing the spindle swivel of a large C-clamp on the piston face, hooking the frame end of the clamp on the back of the caliper, and tightening the clamp. Be careful not to pinch or damage the rubber piston dust boot.

For rear brakes that have the emergency brake incorporated into the brake calipers, hook a large C-clamp over the back of the caliper, and position the clamp spindle swivel on the piston face. Put firm pressure on the piston, by tightening the clamp, but do not try to push the piston back. Grip the piston with large channel lock pliers, and rotate the piston, clockwise, to move it back into the cylinder. Maintain backward pressure on the piston, by tightening the C-clamp after every piston rotation. Be careful not to damage the rubber piston dust boot.

5

Remove any retaining screws or bolts from the disk, and pull the disk straight off the hub. If the disk is seized, tap the center part of the disk, firmly, with a hammer or mallet, taking care not to hit the friction surface or outer rim. Some disks have threaded holes in the center part of the disk. Bolts can be threaded into these holes and tightened to jack a seized disk off the hub.

6

Clean all parts with brake cleaning fluid. Catch the used fluid in a catch pan, and dispose of used fluid properly. Install a new disk, if needed. Liberally lubricate the caliper bolts with brake grease, before reinserting them in their mounts. Reassemble the caliper, using new pads and shims, if needed, and reinstall the caliper. Reinstall the wheel. Repeat the procedure on the other rear wheel.

7

Lower the vehicle. Start the engine, and pump the brakes a few times to re-extend the retracted pistons. Test the brake operation, before driving.