Brake Disc Check

BRAKE DISC CHECK

CAUTION:
Disc brakes must be kept within the allowable service values in order to maintain normal brake operation.

Before turning the brake disc, the following conditions should be checked.






BRAKE DISC THICKNESS CHECK

1. Remove contaminants or corrosion from the brake disc surface.





2. Use a micrometer to measure the brake disc thickness at minimum eight points which are 10 mm (0.39 inch) inward from its circumference.
Standard value:

32.0 mm (1.26 inch)[ Front]

22.0 mm (0.87 inch)[ Rear]
Limit:

30.0 mm (1.18 inch)[ Front]

20.0 mm (0.79 inch)[ Rear]
3. If the brake disc thickness is worn beyond the limit value at more than one point, replace the brake disc and check its run-out.

BRAKE DISC THICKNESS UNEVENNESS CHECK AND CORRECTION

1. Remove contaminants or corrosion from the brake disc surface.





2. Use a micrometer to measure the brake disc thickness at minimum eight points which are 10 mm (0.39 inch) inward from its circumference. Then record the measurements.
3. If the brake disc thickness unevenness (the difference between the maximum and minimum values measured above) is 0.015 mm (0.0006 inch) or less, it is within the standard value.





4. If the brake disc thickness unevenness exceeds the standard value, grind it according to the procedure below while it is mounted on the vehicle.
NOTE:
If it is suspected that the brake disc thickness will become less than the limit value after the grinding, replace the brake disc and check its run-out.

(1) Check for wheel bearing looseness in the axial direction Front Axle [Front], On-vehicle Service, Wheel bearing axial play check Rear Axle [Rear]).
(2)

CAUTION:

- Insert M12 plain washer and then install the adapter as shown before grinding.Failure to use the M12 plain washer will cause the brake disc to be deformed and ground incorrectly.
- To grind the brake disc, ensure that all the nuts (M12 X 1.5) are tightened evenly and in a diagonal sequence to the specified torque [100Nm (74 ft-lb)].Failure to use all the nuts (M12x1.5), excessive or uneven tightening torque will cause the brake disc to deform or judder.

Correct the brake disc uneven thickness by grinding it while in place on the vehicle.

BRAKE DISC RUN-OUT CHECK AND CORRECTION

1. Check for wheel bearing looseness in the axial direction Front Axle [Front], On-vehicle Service, Wheel bearing axial play check Rear Axle [Rear).

2. If the axial play is within the limit value, secure the brake disc by tightening the nut (M12x1.5) evenly to the specified torque [100 Nm (74 ft-lb)].If the axial play still exceeds the limit value, replace the wheel bearing. Then secure the brake disc by tightening the nut (M12x1.5) evenly to the specified torque [100 Nm
(74 ft-lb)].





3. Place a dial gauge ca. 5 mm (0.2 inch) inward from the circumference of the brake disc to measure its run-out.
Limit:

0.06 mm (0.0024 inch)[ Front]
0.08 mm (0.0032 inch)[ Rear]
4. If the brake disc run-out exceeds the limit value, rephase the brake disc to the hub so that the minimum brake disc run-out is obtained.





5.
CAUTION:

- Insert M12 plain washer and then install the adapter as shown before grinding.Failure to use the M12 plain washer will cause the brake disc to be deformed and ground incorrectly.
- To grind the brake disc, ensure that all the nuts (M12 X 1.5) are tightened evenly and in a diagonal sequence to the specified torque [100Nm (74 ft-lb)].Failure to use all the nuts (M12x1.5), excessive or uneven tightening torque will cause the brake disc to deform or judder.

If the brake disc run-out exceeds the limit value after rephasing, grind the disc while in place on the vehicle so that the brake disc run-out is within the limit value.
NOTE:
If it is suspected that the brake disc thickness will be below the limit value, replace the brake disc.Then rephase the brake disc so that the minimum brake disc run-out is obtained, or grind the disc while in place on the vehicle so that its run-out is below the limit value.