Preliminary Inspection

Any servicing of the rotor requires extreme care to maintain the rotor to within service tolerances to ensure proper brake action. Before refinishing or refacing a rotor, the rotor should be checked and inspected for the following conditions:

^ Braking surface scoring, rust, impregnation of lining material and worn ridges.
^ Excessive rotor lateral runout or wobble.
^ Thickness variation in braking surface of the rotor (parallelism).
^ Dishing or distortion in braking surface of the rotor (flatness).
^ If a vehicle has not been driven for a period of time, the rotors will rust in the area not covered by the brake lining and cause noise and chatter when the brakes are applied.
^ Excessive wear and scoring of the rotor can cause temporary improper lining contact if ridges are not removed from braking surface of rotor before installation of new brake shoe assemblies.
^ Some discoloration and/or wear of the rotor surface is normal and does not require resurfacing when linings are replaced.
^ Excessive runout or wobble in a rotor can increase pedal travel due to piston knock-back. This will also increase guide pin bushing wear due to the tendency of the caliper to follow rotor wobble.
^ Thickness variation in a rotor can also result in pedal pulsation, chatter and surge due to variation in brake output. This can also be caused by excessive runout in the rotor and/or the hub.
^ Dishing or distortion can be caused by extreme heat and abuse of the brakes.