How to Repair Disc Brakes

Disc brakes work with large metal discs that turn with the wheels and are squeezed by the brake pads to stop. Over time, the discs can become worn down and damaged, especially if you leave worn out brake pads installed. Brakes with bad pads can cut grooves into the discs. If you see this while changing your brakes, the discs need to be repaired by having a professional refinish them, if not replaced outright.

Instructions

1

Raise one end of the vehicle-- front or back--on jack stands and remove the wheels. It helps to loosen the lug nuts before raising the vehicle.

2

Remove the caliper from the disc by disconnecting its mounting bolts. If the caliper is in good condition, hang it somewhere out of the way with a strong wire--never let it hang by the brake hose. If the caliper is damaged, disconnect it from the hose by removing the banjo bolt and replace the caliper.

3

Disconnect the lug nuts and/or retaining screws to remove the disc from the vehicle. If the mounting screws are stuck, loosen them with an impact screwdriver. If the disc is stuck on the rotor, thread two bolts into the open holes that are on the disc and tighten them to force the disc off.

4

Remove any glaze from the disc's surface by running an emery cloth or sandpaper across it in a swirling motion.

5

Take the disc to an automotive machine shop to refinish or machine the disc. The disc cannot be refinished to where it is thinner than its specified minimum thickness. This thickness is stamped or cast into the disc and can be measured with a micrometer.

6

Fit the disc back onto its rotor and apply its lug nuts or screws. Reconnect the caliper to the disc with its mounting bolts, replace the wheel and lower the vehicle.