Brake Rotor Surface and Wear Inspection
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Refer to Brake Dust Caution
in Cautions and Notices.
- If the inboard friction surface of the brake rotor is not accessible, reposition and support the caliper with the brake pads. Refer to Brake Pads Replacement - Front and/or Brake Pads Replacement - Rear (All except 1500 Series W/O NYS) or Brake Pads Replacement - Rear (15 Series W/O NYS) .
- 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
- Heavy rust and/or pitting
- If the friction surfaces of the brake rotor exhibit one or more of the Braking Surface Conditions, the rotor requires refinishing or replacement.
- Using a micrometer calibrated in thousanths-of-a-millimeter, or ten-thousanths-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.