Brake Rotors (1997): Notes

CAUTION: The rear brake rotor used on this vehicle cannot be machined. If when diagnosing rear rotor for thickness variation and runout it is found not to meet required specifications, rotor must be replaced. No attempt should ever be made to machine rear brake rotor.

Any servicing of rotor requires extreme care to maintain rotor to within service tolerances to ensure proper brake action. Before refinishing or refacing a rotor, rotor should be checked and inspected for 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 rotor (Parallelism). Dishing or distortion in braking surface of rotor (Flatness).

If a vehicle has not been driven for a period of time, rotors will rust in area not covered by brake lining and cause noise and chatter when brakes are applied. Excessive wear and scoring of rotor can cause temporary improper lining contact if ridges are not removed from braking surface of rotor before installation of new brake shoes. Some discoloration and/or wear of 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 tendency of 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 rotor and/or hub. Dishing or distortion can be caused by extreme heat and abuse of brakes.