How to Change Rear Brake Pads

Knowing how to change rear brake pads may not seem important, since front brakes provide as much as 80% of the required braking power. Rear brakes pads are important, however, as they are often responsible for providing stopping power for the emergency brake system.

Servicing Rear Brake Pads

• Buy the book. A service manual will make your life easier when it comes to replacing rear brake pads. Attachment systems vary by manufacturer, and a service manual will tell you the exact way to uninstall your rear brake pads and how to install new ones.
• You must know jack. Block the front tires, so the car won't slip off the jack. Loosen the lug nuts on the rear wheels. Jack the back of the car up, placing jack stands under the car to hold it up. Remove the rear wheels.
• Before you begin. Using brake cleaner, remove dust and grime from the rear brake area. Be careful not to breathe brake dust. While working on one wheel, leave the other wheel assembled for reference. Also, loosen the cap on the master cylinder reservoir located in the engine compartment to relieve pressure during the replacement process.
• Remove the calipers. The rear brake calipers are mounted so that they sit over a portion of the rotor (the shiny metal disk around the wheel hub). On smaller cars, the calipers may be spring mounted, but on most cars, the calipers are bolted to a supporting bracket. Remove the calipers, leaving the brake line hoses attached. NOTE: The caliper is connected to a flexible tube that carries the brake fluid. Place or hang the caliper (using bailing wire or a bungee cord) out of the way so the brake fluid hose doesn't become loose or damaged.
• Remove pads. Remove the rear brake pads, noting carefully the position of the pads and any tabs, shims or restraining clips. Here's where a service manual comes in handy.
• Inspect the rotor. While the caliper and pads are removed, check the status of the rear brake rotor (the shiny wheel that fits inside the caliper). If the rotor is dull, scored or has a haze on its surface, it will need to be replaced or refinished.
• Reset the piston. As the rear brake pads wear down, the caliper piston expands to hold them in place. The piston will need to be compressed to its original position before the new rear brake pads can be installed. While some pistons can be compressed using a c-clamp, others need to be screwed back into position using a special tool. Check your service manual for details. NOTE: While compressing the caliper piston, be sure to keep an eye on the brake fluid level and remove some fluid if the reservoir looks like it might overflow.
• Install the new pads. Put the new rear brake pads in place, replacing any clips or shims and making sure that tabs are properly aligned. You may want to put a coating of brake grease on the outside of the brake pads to limit noise later. Make sure not to get any grease on the rotor side of the brake pads-if you do, be sure to remove it with brake cleaner.
• Re-install the caliper. Carefully return the caliper to its original position and secure it by tightening the mounting bolts. Now you can move on to the other wheel.
• Breaking new pads in. Before you take your car out on the road, gently pump the brakes a few times to reset the caliper pistons. Once the pistons are set, repeatedly use the brakes slowly while traveling at a low (under 25mph) rate of speed. After a couple of dozen times, the new brake pads will be properly seated and burnished for normal driving.