Grand Voyager V6-3.8L VIN L (1999)
Brake Rotor/Disc: Testing and Inspection
Any servicing of the rotor requires extreme care to maintain the rotor within service tolerances to ensure proper brake action.
Excessive runout or wobble in a rotor can increase pedal travel due to piston knock-back. This increases guide pin sleeve wear due to the tendency of
the caliper to follow the rotor wobble.
When diagnosing a brake noise or pulsation, the machined disc braking surface should be checked and inspected.
BRAKING SURFACE INSPECTION
Light braking surface scoring and wear is acceptable. If heavy scoring or warping is evident, the rotor must be refaced or replaced.
Excessive wear and scoring of the rotor can cause improper lining contact on the rotor's braking surface. If the ridges on the rotor are not removed
before new brake pads are installed, improper wear of the pads will result.
If a vehicle has not been driven for a period of time, the rotor's braking surface will rust in the areas not covered by the brake pads at that time. Once
the vehicle is driven, noise and chatter from the disc brakes can result when the brakes are applied.
Some discoloration or wear of the rotor surface is normal and does not require resurfacing when linings are replaced. If cracks or burned spots are
evident, the rotor must be replaced.
ROTOR MINIMUM THICKNESS
Measure rotor thickness at the center of the brake pad contact surface. Replace the rotor if it is worn below minimum thickness or if machining the
rotor will cause its thickness to fall below specifications.
CAUTION: Do not machine the rotor if it will cause the rotor to fall below minimum thickness.
Minimum Brake Rotor Thickness Markings (Typical)
Minimum thickness specifications are cast on the rotor's unmachined surface. Limits can also be found in SPECIFICATIONS.
ROTOR THICKNESS VARIATION
Thickness variation in a rotor's braking surface can result in pedal pulsation, chatter and surge. This can also be caused by excessive runout in the
rotor or the hub.
