Brake disc - inspection, renovation or renewal

Braking system / Brake disc - inspection, renovation or renewal

1 Whenever the front disc pads are being checked for wear, take the opportunity to inspect the discs for deep scoring or grooving. After a high mileage the disc may become reduced in thickness away from the extreme outer edge of the disc. lf this wear is rapid, it is possible that the friction pads are of too hard a type.

2 If the disc has evidence of many tiny cracks, these may be caused by overheating due to a seized caliper piston in the “applied” position.

3 The foregoing conditions may be corrected by regrinding the disc provided that the thickness of the disc is not reduced below that specified by such action. Alternatively, fit a new disc.

4 To remove a disc, take off the caliper and pads as described in Sections 3 and 5. Tie the caliper up, out of the way.

5 Knock back the tabs of the lockplates and unbolt the caliper support bracket from the hub carrier.

6 Unscrew and remove the two bolts which hold the disc assembly to the hub. One of these bolts is for wheel locating purposes.

7 Pull the disc from the hub.

8 Refitting is a reversal of the removal process. If the disc has excessive run-out, repositioning it in relation to the hub may bring it within tolerance by cancelling out the run-out characteristics in the hub and disc, once the most suitable fitted position has been found.