Disc Brake System: Service and Repair

Brake Disc Runout Check





Special Tool(s)

Check
1. Loosen the wheel nuts.
2. Raise and support the vehicle.
3. Remove the wheel.
4. Remove the brake pads.
5. Reverse and install the wheel nuts to hold the brake disc in place.
6. Install a dial indicator gauge and holding fixture to the suspension strut.





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

Using a suitable dial indicator gauge 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.
8. Check the brake disc thickness variation.
^ Using a suitable micrometer measure the disc thickness at eight positions 45 degrees apart and 15 mm in from the outer edge of the brake disc.
^ If any of the readings vary by 0.015 mm or more, or the brake disc thickness is less than the specified minimum, a new brake disc should be installed.





9. Remove the brake disc.





10. 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 given specification. Install a new wheel hub and recheck.
11. If the hub face runout is within specification install a new brake disc and recheck the brake disc run-out.