Brake Rotor Thickness Measurement

Brake Rotor Thickness Measurement

Caution: Refer to Brake Dust Caution, refer to Service Precautions.
Brake Dust Caution


1. If the inboard friction surface of the brake rotor is not accessible, reposition and support the caliper with the brake pads.
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 (1/2 inch), for each measurement.

4. Compare the lowest thickness measurement recorded to the following specifications:

+ Specification-Front Brake
- Brake rotor minimum allowable thickness after refinishing 28.0 mm (1.10 inch)
- Brake rotor discard thickness 27.50 mm (1.082 inch)

+ Specification-Rear Brake
- Brake rotor minimum allowable thickness after refinishing 29.0 mm (1.142 inch)
- Brake rotor discard thickness 28.50 mm (1.122 inch)

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.