SMU - Revised Brake Rotor Thickness Measurement Procedure

This bulletin is being issued to revise the Brake Rotor Thickness Measurement procedure in the Disc Brakes sub-section of the Service Manual. Please replace the current information in the Service Manual with the following information.

The following information has been updated within SI. If you are using a paper version of this Service Manual, please make a reference to this bulletin on the affected page.

Caution: Refer to Brake Dust Caution in Cautions and Notices.

Brake Rotor Thickness Measurement

1. If the inboard friction surface of the brake rotor is not accessible, reposition and support the caliper with the brake pads. Refer to Brake Pads Replacement - Front and/or Brake Pads Replacement - Rear.
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 (½ in), 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 (1.102 in)

•	Brake rotor discard thickness 27.50 mm (1.083 in)

Specification - Rear Brake

•	Brake rotor minimum allowable thickness after refinishing 19.0 mm (0.748 in)

•	Brake rotor discard thickness 18.5 mm (0.728 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.