Brake Rotor Thickness Measurement

Brake Rotor Thickness Measurement

^ Tools Required
- J 26900-1 Combimike Micrometer

1. Reposition and support the caliper and the brake pads.
2. Clean the brake pad lining contact surfaces of the brake rotor with denatured alcohol or an equivalent brake cleaner.





3. Use the J 26900-1, or the equivalent micrometer, in order to measure the thickness of the brake rotor. Measure the thickness of the rotor at 4 or more points equally spaced around the rotor. Position the J 26900-1, or the equivalent, at the same distance from the outside edge of the rotor, in the brake pad lining contact area.
4. Compare the measurements to the following specifications:
^ The discard specification for the front brake rotor is 30.0 mm (1.181 in).
^ The discard specification for the rear brake rotor is 16.0 mm (0.630 in).
5. If the smallest measurement exceeds the discard specification, you may be able to resurface the brake rotor, depending upon the thickness variation and the surface condition. Refer to Brake Rotor Thickness Variation Measurement and to Brake Rotor Surface and Wear Inspection.
6. If the smallest measurement is equal to or less than the discard specification, replace the brake rotor.