Brake Rotor Thickness Measurement (With ZL1 (Front))

Brake Rotor Thickness Measurement (With ZL1 (Front))

Warning: Refer to Brake Dust Warning Brake Dust Warning.


Note: Due to the floating design of the brake rotor, the front brake rotor cannot be refinished. If the front brake rotor is found to be at or below the minimum specification, it must be replaced.

Note: Do not remove the brake rotor from the wheel hub.

1. If the inboard friction surface of the brake rotor is not accessible, reposition and support the brake caliper with the brake pads. Refer to Front Brake Rotor Replacement (LFX) Front Brake Rotor ReplacementFront Brake Rotor Replacement (L99, LS3) Front Brake Rotor ReplacementFront Brake Rotor Replacement (LSA) Front Brake Rotor 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 thousanths-of-a-millimeter, or ten-thousanths-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 in),
for each measurement.

4. Compare the lowest thickness measurement recorded specifications. Refer to Disc Brake Component Specifications Disc Brake Component Specifications.

5. If the lowest thickness measurement of the brake rotor is above the brake rotor discard thickness specification, the rotor may be able to be reused, 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 brake rotor discard thickness specification, the rotor requires replacement.