Brake Rotor/Disc: Testing and Inspection

WARNING: Never use an air hose or dry brush to clean brake assemblies. Use an OSHA-approved vacuum cleaner to avoid breathing brake dust.

DISC RUNOUT

- Loosen the rear wheel nuts slightly, then raise the vehicle and support it on safety stands. Remove the rear wheels.

- Remove the brake pads.

- Inspect the disc surface for damage and cracks. Clean the disc thoroughly and remove all rust.

- Use wheel nuts and suitable plain washers to hold the disc securely against the hub, then mount a dial indicator as shown and measure the runout at 10 mm (0.4 in) from the outer edge of the disc.

Specs:
Max Refinishing Limit: 8.0 mm (0.31 in).

Rear Disc Dial Indicator:

- If the disc is beyond the service limit, replace the brake disc.


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

DISC THICKNESS AND PARALLELISM

Rear Disc Micrometer Setup:

- Using a micrometer, measure disc thickness at eight points, approximately 45° apart and 10 mm (0.4 in) in from the outer edge of the disc.

Specs:
Brake disc thickness 9.9-10.1 mm (0.39-0.40 in)
Max refinishing limit 8.0 mm (0.31 in)
Brake Disc Parallelism 0.015mm (0.31 in) max.

NOTE: Replace the brake disc if the smallest measurement is less than the max. refinishing limit. This is the maximum allowable difference between the thickness measurements.

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

NOTE: Refer to Steering and Suspension for brake disc replacement.