Rotor/Disc Thickness Check

1. Using a micrometer, measure disc thickness at eight positions, approximately 45° apart and 10 mm (0.39 inch) in from the outer edge of the disc.
- Brake disc thickness standard value is 18.0 mm (0.71 inch) and the limit is 16.4 mm (0.65 inch)
- Thickness variation, measured from at least 8 positions, is the difference between any thickness measurements should not be more than 0.015 mm (0.0006 inch).
2. If the disc is beyond the limits for thickness, remove it and install a new one. If thickness variation exceeds the specification, replace the brake disc or turn the rotor with an on-car type brake lathe ("Accuturn-8750" or equivalent).