Brake Rotor Thickness Measurement

Brake Rotor Thickness Measurement

^ Tools Required
- J 26900-1 Combimike Micrometer





1. Clean the brake pad lining contact surfaces of the brake rotor with denatured alcohol or an equivalent brake cleaner.
2. Use the J 26900-1, or the equivalent, 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.
3. Compare the measurements to the following specifications:
^ The maximum thickness variation is 0.013 mm (0.0005 inch).
^ The minimum thickness of the brake rotor after resurfacing is 15.0 mm (0.590 inch).
4. If the thickness variation exceeds the specification, compare the smallest measurement to the minimum thickness specification,
5. If the smallest measurement exceeds the minimum thickness specification, you may be able to resurface the brake rotor, depending upon the surface and wear conditions which may be present.
6. If the smallest measurement is less than the minimum thickness specification, replace the brake rotor.