Brake Rotor Thickness Variation Measurement
Check thickness variation by measuring the rotor thickness at four or more points around the circumference of the rotor. Use a micrometer calibrated in ten-thousandths 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) can cause pedal pulsation and/or front end vibration during brake applications. A rotor that does not meet these specifications should be refinished to specifications or replaced.