LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 511 (Disc Brakes (Cab & Chassis, & Hd)) >> Adjustments & Inspection >> Brake Rotor Surface & Wear Inspection

Brake Rotor Surface & Wear Inspection

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Required Tool: Dial Indicator Set (J-8001).
  1. Raise and support the vehicle.
  2. Remove the tire and wheel assemblies.
  3. Clean the brake pad lining contact surfaces of the brake rotor with denatured alcohol or an equivalent approved brake cleaner.
  4. Inspect the braking surfaces of the brake rotor for the following braking surface conditions:
    • Heavy rust and/or pitting.
    • Cracks and/or heat spots.
    • Excessive blueing discoloration.
  5. Light surface rust can be removed with an abrasive disc. If the braking surfaces of the brake rotor exhibits one or more of the remaining conditions then the brake rotor requires refinishing or replacement.
  6. Using a calibrated micrometer measure and record the thickness variation of the brake rotor at 4 or more points around the rotor. Ensure that the measurements are only taken within the brake pad lining contact area and that the micrometer is positioned the same distance from the outside edge of the rotor for each measurement. See Figure .
  7. Compare the thickness variation recorded to the brake rotor maximum allowable thickness variation. See DISC BRAKE SPECIFICATIONS  .
  8. If the brake rotor thickness variation exceeds the specification, the brake rotor requires refinishing. See BRAKE ROTOR REFINISHING  under SERVICING.
  9. Using the micrometer measure and record any grooves present on the rotor braking surface.
  10. Compare the groove/scoring depth recorded to the brake rotor maximum allowable scoring. See DISC BRAKE SPECIFICATIONS  .
  11. If the brake rotor scoring depth exceeds the specification or if an excessive amount of scoring is present, the brake rotor requires refinishing. See BRAKE ROTOR REFINISHING  under SERVICING.
    NOTE: Ensure the wheel bearings are properly adjusted before proceeding with the following steps.
  12. Mount a dial indicator set or equivalent, and position the indicator button so it contacts the brake rotor at a 90 degree angle, approximately 0.5" (13 mm) from the rotor's outer edge. See Fig 1 .
  13. Measure and record the lateral runout of the brake rotor.
    1. Rotate the rotor until the lowest reading is displayed on the indicator dial, then zero the dial.
    2. Rotate the rotor until the highest reading is displayed on the dial.
  14. Compare the lateral runout reading to the brake rotor maximum allowable lateral runout. See DISC BRAKE SPECIFICATIONS  .
  15. If the brake rotor lateral runout exceeds the specification, the brake rotor requires refinishing. See BRAKE ROTOR REFINISHING  under SERVICING.
Fig 1: Measuring Rotor Runout
G00310120Courtesy of GENERAL MOTORS CORP.
scientia non olet · About LEMON Manuals