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Brake Rotor Thickness Measurement

Brake Rotor Thickness Measurement


Refer to Brake Dust Warning .


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 (J60, J61) Front Disc Brake Pads Replacement (J62) and/or Rear Disc Brake Pads Replacement (J60) Rear Disc Brake Pads Replacement (J61, J62) , if equipped.


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 lowest thickness of the brake rotor at 4 or more points, equally 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 outside edge of the rotor, about 13 mm (1/2 in), for each measurement.

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

Specification - Front


Brake rotor minimum allowable thickness after refinishing: 28 mm (1.102 in)

Brake rotor discard thickness: 27 mm (1.07 in)


Specification - Rear


Brake rotor minimum allowable thickness after refinishing:

16 inch rotor: 11 mm (0.433 in)

17 inch rotor: 22 mm (0.866 in)

Brake rotor discard thickness:

16 inch rotor: 10.0 mm (0.395 in)

17 inch rotor: 21.0 mm (0.827 in)


1. 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.

2. 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.

3. If the lowest thickness measurement of the brake rotor is at or below the discard thickness specification, the rotor requires replacement. Refer to Front Brake Rotor Replacement (J60, J61, J62) or Rear Brake Rotor Replacement (J60) Rear Brake Rotor Replacement (J61, J62) .