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.
Rotor thickness variation measurements should be made in conjunction with measuring runout. Measure thickness of the brake rotor (2) at 12 equal points around the rotor braking surface with a micrometer (1) at a radius approximately 25 mm (1 inch) from edge of rotor. If thickness measurements vary beyond the specification listed in the specification table, the rotor should be refaced or replaced. Refer to ROTOR, BRAKE, SPECIFICATIONS and ROTOR, BRAKE, STANDARD PROCEDURE .