For 1990-2009 cars

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 or to Rear Disc Brake Pads Replacement as applicable.
2. Clean the brake pad lining contact surfaces of the brake rotor with denatured alcohol or an equivalent brake cleaner.
3. Using a micrometer calibrated in thousandths-of-a-millimeter, or ten-thousandths-of-an-inch, 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 micrometer 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:

Specifications

• | The discard specification for the front brake rotor is 27.40 mm (1.079 in).

• | The discard specification for the rear brake rotor is 18.40 mm (0.724 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. Refer to Front Brake Rotor Replacement or to Rear Brake Rotor Replacement as applicable.