Brake Rotor Surface and Wear Inspection

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

WARNING: Refer to Brake Dust Warning .

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 and/or Rear Disc Brake Pads Replacement .
Clean the friction surfaces of the brake rotor with denatured alcohol, or an equivalent approved brake cleaner.
Inspect the friction surfaces of the brake rotor for the following Braking Surface Conditions:
- Heavy rust and/or pitting
  Light surface rust can be removed with an abrasive disc. Heavy surface rust and/or pitting must be removed by refinishing the rotor.
- Cracks and/or heat spots
- Excessive blueing discoloration
If the friction surfaces of the brake rotor exhibit one or more of the Braking Surface Conditions, the rotor requires refinishing or replacement.

Fig 1: Measuring Brake Rotor Thickness

Courtesy of GENERAL MOTORS CORP.

Using a micrometer calibrated in thousandths-of-a-millimeter, or ten-thousandths-of-an-inch, measure and record the scoring depth of any grooves present on the rotor friction surfaces.
Compare the groove scoring depth recorded to the following specification:
Specification: Brake rotor maximum allowable scoring: 1.50 mm (0.059 in)
If the brake rotor scoring depth exceeds the specification, or if an excessive amount of scoring is present, the rotor requires refinishing or replacement.