Brake Rotor/Disc: Testing and Inspection

INSPECTION

RUNOUT

1. Raise the rear or the vehicle, and make sure it is securely supported.
2. Remove the brake pads.
3. Inspect the disc surface for damage and cracks clean the disc thoroughly and remove all rust.
4. Use wheel nuts and suitable flat washers (A) to hold the disc securely against the hub, then mount a dial indicator (B) as shown, and measure the runout at 10 mm (0.4 in.) from the outer edge of the disc.





5. If the disc is beyond the service limit, refinish the brake disc.

Max. Refinishing limit: 8.0 mm (0.315 in.)

NOTE: A new disc should be refinished if its runout is greater than 0.10 mm (0.004 in.)

THICKNESS AND PARALLELISM

1. Loosen the rear wheel nuts slightly, then raise the vehicle, and make sure it Is securely supported. Remove the rear wheels.
2. Remove the brake pads.
3. Using a micrometer (A), measure disc thickness at eight points, approximately 45 apart and 10 mm (0.4 in.) in from the outer edge of the disc. Replace the brake disc if the smallest measurement is less than the max. refinishing limit.

Brake disc thickness:
Standard: 10 mm (0.4 in.)
Max. Refinishing limit: 8.0 mm (0.315 in.)
Brake disc parallelism: Max. 0.015 mm (0.0006 in.)

This is the maximum allowable difference between the thickness measurements.





4. If the disc is beyond the service limit for parallelism, refinish the brake disc.

NOTE: If the brake disc is beyond the service limit for refinishing, replace it.