Brake Rotor/Disc: Testing and Inspection

Brake Disc Runout Check





Special Tool(s)
Check
1. Remove the brake pads.
2. Reverse and install the wheel nuts to hold the brake disc in place.





3. Check the brake disc thickness variation.
- Using a suitable micrometer measure the disc thickness at eight positions 45 degrees apart and 15 mm (0.59 inch) from the outer edge of the brake disc.
- If any of the readings vary by 0.020 mm (0.0008 inch) or more, the brake disc requires machining.
4. Install the special tool to the suspension strut.





5. NOTE: If the runout is outside the specification, check the wheel hub face runout.

Measure the inner and outer faces of the disc.
1 Position the gauge so that it contacts the disc 10 mm (0.4 inch) from the outer edge.
2 Slowly rotate the disc. The total dial reading should not exceed the given specification.
6. Remove the brake disc.





7. NOTE: Make sure the wheel hub face is clean and free of rust and foreign material.

Using the special tool, check the wheel hub face runout.
- Slowly rotate the wheel hub and check the runout. If the runout exceeds the brake disc runout specification, install a new wheel hub and recheck.
8. If the hub face runout is within the brake disc runout specification, install a new brake disc and recheck the brake disc runout.