XK-8 Convertible (X100) V8-4.0L (AJ27) (2001)
disc when the wheel and disc assembly is described.
Brake drag, which is the continued contact of the pad on the disc, caused by a piston or caliper not retracting after a brake application, will
cause accelerated, and possibly uneven, wear.
Movement of the hub and disc assembly relative to the axle center line caused by insecure or worn bearings.
The following workshop checks are intended as an aid to the understanding and diagnosis of brake disc concerns, but do not constitute an
instruction to proceed with repair work.
Check that caliper and pistons move freely.
If variations in the disc thickness are suspected, measure the thickness of the disc at regular radial intervals within the wear pattern.
When the vehicle has been in service for some time, measure the thickness of the discs to ensure that they are above the minimum limits.
If brake drag is suspected, remove the caliper and inspect and clean the guide pins and their housings.
Checking hub and brake disc run-out
With the wheel and brake disc removed, use a suitable dial indicator gauge to check the hub end float. If the end float exceeds the limit of 0.05
mm., (0.002 in.), check the hub bearing assembly for damage.
Use the dial indicator gauge to check the hub run-out by rotating the hub. If the hub run-out exceeds the limit, check the hub bearing assembly for
Reinstall the disc on the hub and retain it in position with at least three lug nuts, after ensuring that the mating faces are clean.