Check for thickness variation by measuring the rotor thickness at four or more points around the circumference of the rotor (1-4). 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 front rotor that varies in thickness by more than 0.010 mm (0.0003 in) or, a rear rotor that varies in thickness by more than 0.013 mm (0.0005 in) can cause brake pedal pulsation and/or vehicle vibration during brake applications. Refinish to specifications or replace a rotor that does not meet these specifications.