Brakes
Learn About Your Brakes
Why do Brake Rotors need to be replaced?
When brake pads are compressed against the rotor, the friction created stops the vehicle. This friction eventually wears not only the brake pads, but also the rotor. Rotors develop wear patterns from the brake pads over time. When a worn brake pad is replaced, rotors need to be machined smooth to remove the wear patterns. A rotor can be machined smooth only so many times before it is worn too much. Each rotor must have a certain width, which is inscribed on the rotor, and if the rotor is too worn, it must be replaced. Over time, rotors can also develop heat cracks and other damage.
Another reason for replacing brake rotors is oxidation, commonly referred to as "rust". Over time, the large metal surfaces of the brake rotor are exposed to moisture. With vehicles that are not driven regularly, the moisture and condensation that accumulates on the surface of the rotor is not given the chance to heat up and dissipate, which results in oxidation. When the oxidation develops into visble rust, dissipation of the heat in the brake rotors that is generated by the brakes becomes inefficient and can cause the surface of the brake rotor to distort and become warped. When the brake rotors become warped, this distortion in the surface of the rotor is transferred hydraulically to the brake pedal and results in a "pulsating" of the brake pedal when the brakes are applied. This pulsation in the brake pedal, in turn, may prohibit the vehicle from stopping properly.