Brake Rotor Thickness Variation Measurement
Test thickness variation by measuring the rotor thickness at 4 or more points around the circumference of the rotor. Use a micrometer calibrated in ten-thousands of an inch. Make all measurements at the same distance in from the edge of the rotor.A rotor that varies in thickness by more than 0.013 mm (0.0005 inch) may cause pedal pulsation and/or front end vibration during brake application. Replace or refinish to specifications, a rotor that does not meet these specifications.