Brake Rotor/Disc: Testing and Inspection
FRONT DISC BRAKE ROTOR CHECKCAUTION: When servicing disc brakes, it is necessary to exercise caution to keep the disc brakes within the allowable service values in order to maintain normal brake operation.
Before re-finishing or re-processing the brake disc surface, the following conditions should be checked.
FRONT BRAKE DISC THICKNESS CHECK
1. Using a micrometer, measure disc thickness at eight positions, approximately 45° apart and 10 mm (0.39 inch) in from the outer edge of the disc.
Brake disc thickness
Standard value:
18.0 mm (0.71 inch)
24.0 mm (0.94 inch)
Minimum limit:
16.4 mm (0.65 inch)
22.4 mm (0.88 inch)
Thickness variation (at least 8 positions)
The difference between any thickness measurements should not be more than 0.015 mm (0.0006 inch).
2. If the disc is beyond the limits for thickness, remove it and install a new one. If thickness variation exceeds the specification, replace the brake disc or turn rotor with on the car type brake lathe ("Accuturn-8750" or equivalent).
FRONT BRAKE DISC RUN-OUT CHECK
1. Remove the caliper support; then raise the caliper assembly upward and secure with a wire.
2. Inspect the disc surface for grooves, cracks and rust. Clean the disc thoroughly and remove all rust.
3. Place a dial gauge approximately 5 mm (0.2 inch) from the outer circumference of the brake disc, and measure the run-out of the disc.
Limit: 0.06 mm (0.0024 inch) or less
NOTE: Tighten the nuts in order to secure the disc to the hub.