Brake Rotor Thickness Measurement

Brake Rotor Thickness Measurement

Caution:Avoid taking the following actions when you service wheel brake parts:
- Do not grind brake linings
- Do not sand brake linings
- Do not clean wheel brake parts with a dry brush or with compressed air
Some models or aftermarket brake parts may contain asbestos fibers which can become airborne in dust. Breathing dust with asbestos fibers may cause serious bodily harm. Use a water-dampened cloth in order to remove any dust on brake parts. Equipment is available commercially in order to perform this washing function. These wet methods prevent fibers from becoming airborne.

1. If the inboard friction surface of the brake rotor is not accessible, reposition and support the caliper with the brake pads. Refer to Front Disc Brake Pads Replacement and/or Rear Disc Brake Pads Replacement.
2. Clean the friction surfaces of the brake rotor with denatured alcohol, or an equivalent approved brake cleaner.






3. Using a micrometer calibrated in thousandths-of-a-millimeter, or ten-thousandths-of-an-inch, measure and record the thickness of the brake rotor at four or more points, evenly spaced around the rotor.
- Ensure that the measurements are only taken within the friction surfaces and that the micrometer is positioned the same distance from the outer edge of the rotor, about 13 mm (� in), for each measurement.
4. Compare the lowest thickness measurement recorded to the following specifications:
- Front brake rotor minimum allowable thickness after refinishing: 31.08 mm (1.224 in).
- Front brake rotor discard thickness: 30.7 mm (1.209 in).
- Rear brake rotor minimum allowable thickness after refinishing: 10.25 mm (0.404 in).
- Rear brake rotor discard thickness: 9.00 mm (0.354 in).
5. If the lowest thickness measurement of the brake rotor is above the minimum allowable thickness after refinishing specification, the rotor may be able to be refinished, depending upon surface and wear conditions which may be present.
6. If the lowest thickness measurement of the brake rotor is at or below the minimum allowable thickness after refinishing specification, the rotor may not be refinished.
7. If the lowest thickness measurement of the brake rotor is at or below the discard thickness specification, the rotor requires replacement.