Disc run-out check

5. Remove 2 screws securing disc to drive flange.
6. Remove brake disc from drive flange using jacking screws if necessary.

Refit

CAUTION: Excessive disc run-out can exist after fitting a new disc, with no immediate symptoms being evident whilst driving. The most likely cause of run-out is the presence of contaminants (e.g. rust or paint) or damage to the mating faces of disc and flange, and disc and wheel. Excessive run-out will cause progressive uneven wear of the disc, leading to disc thickness variation, which is the cause of judder. Always ensure that the disc run-out check given here is strictly adhered to.

1. Inspect mating surfaces of new disc and drive flange and clean throughly using a wire brush.
2. Fit brake disc to drive flange.
3. Fit and tighten screws to 5 Nm.
4. Fit caliper and finger tighten top mounting bolt.

Disc run-out check

5. Mount a dial test indicator to caliper lower mounting using tool 18G 191-9 and tighten bolt. Tighten top mounting bolt.
6. Position dial test indicator probe 5 mm from disc outer edge.
7. Rotate disc at least one turn and measure disc run-out.

DATA:

Disc run-out limit with wheel on = 0.040 mm.

Run-out exceeds limit

8. Mark wheel to stud relationship. remove wheel, again check mating surfaces for contaminants, then refit wheel 90° from previous position and recheck run-out.
9. If run-out is still excessive, move wheel through a further 90° and recheck run-out.
10. If run-out is still excessive, fit a new road wheel.

Run-out within limit

11. Remove dial test indicator and tool 18G 191-9
12. Fit caliper lower mounting bolt and tighten both bolts to 108 Nm
13. Remove stand(s) and lower vehicle.