Brake Disc Front, Checking

Brake disc front, checking

Special tools:
999 7104 Clamp ring 999 7104 Clamp Ring
999 5418 Measuring kit 999 5418 Measuring Kit
981 4031 Torque socket 19 mm 981 4031 Torque Socket 19 mm

Note! The illustrations in this service information are used for different model years and/or models. Some variation may occur. However, the essential information in the illustrations is always correct.

Preparatory work


Remove:
- the wheel
- the mounting screws for the brake caliper holder.
Hang up the brake caliper in a suitable position.

Installation

Installing the clamp ring




Install: 999 7104 Clamp ring 999 7104 Clamp Ring , included in test tool kit: 999 5418 Measuring kit 999 5418 Measuring Kit , on the hub with the wheel nuts.
Ensure that mating surfaces on the brake disc and clamp ring are clean.
Tighten the studs lightly. Then tighten the screws crosswise. Tighten to 90 Nm.
When tightening with impact wrench, use: 981 4031 Torque socket 19 mm 981 4031 Torque Socket 19 mm.

Installing the bracket




Use the M12x40 wing screws and the M12 nuts from: 999 5418 Measuring kit 999 5418 Measuring Kit.

Measuring lateral run-out




Install the dial gauge in the bracket as illustrated.
Position the tip of the dial gauge against the brake disc. Rotate the brake disc. Use a socket to help. Note the test gauge run-out. Brake disc lateral run-out must not exceed 0.075 mm.
If lateral run-out exceeds the value, replace the brake disc.

Note! Always check the wheel hub's lateral runout according to: Wheel hub front, checking Wheel Hub Front, Checking before installing a new brake disc.

To replace the brake disc, see: Front brake disc, B5254T7, AW55-50/51SN, B5254T7, M66 Brake Disc Front, Replacing.
To replace the brake disc, turbo Sports Wagon, see: Front brake disc, B5254T7, AW55-50/51SN, B5254T7, M66 Brake Disc Front, Replacing.

Finishing

Remove the test equipment.
Install the caliper holder and the brake caliper. Use new screws on the caliper holder.
Tighten, see: Tightening torque [1][2]Specifications.
Install the wheel. See: Wheels Service and Repair.