Replacing brake rotors requires the new rotors and brake fluid. In many cases, bad rotors cause worn brake pads that require replacement. While servicing the rotors, the owner should inspect the wheel bearings and replace them if they show signs of wear.
When changing disc brake pads, owners should check the thickness of rotors, using a micrometer. Manufacturers stamp the minimum thickness of the rotor into the metal at the edge of the unit. Rotors with less than the minimum thickness, that are warped or that have grooves from wear require replacement. Operating a vehicle with worn rotors increases the braking distance and decreases the car's ability to dissipate the heat created in the braking process. The heat buildup has the potential to vaporize brake fluid, causing brake failure.
Each time the driver presses the brake pedal, the pads apply thousands of pounds of force to the rotors, eventually wearing them down. Owners should check brake rotors every 15,000 to 25,000 miles to ensure they remain within specifications. Worn rotors jeopardize the safety of all passengers in the vehicles and others on the road.
After replacing worn rotors and pads, the owner must bleed the brakes. Before beginning the process, he should ensure the brake fluid reservoir is full. He must add more brake fluid while bleeding the brakes and should top off the reservoir at the end of the process.