2. Measure the thickness of the brake discs. In workshops, a micrometer or a special caliper (035) is used for this, since a ridge forms on the edge of the disc when worn. You can also measure the thickness of the discs with a regular caliper, but in this case, a rigid lining should be used on each side of the brake disc (for example, 2 coins). To find out the thickness of the disc, the thickness of the gaskets should be subtracted from the readings.
Note! For more precise measurements using a micrometer, measurements must be taken at least at eight points on the disc. The thickness must remain constant within a tolerance of 0.02 mm.
3. Once the minimum thickness is reached, the brake pads can be changed again. If the wear limit is reached, replace the brake discs.
4. Cooled brake discs with thin cracks up to 25 mm in length, which may occur due to high loads, do not need to be replaced. In case of large cracks or unevenness deeper than 0.5 mm, replace the discs.
5. Repair of brake discs is not allowed. Both discs on the axle must be replaced.
6. If a dial indicator is available, measure the lateral runout of the brake disc in the assembled state. Place the small movement dial indicator in the center of the braking surface.
Caution! Excessive lateral runout may be due to increased clearance in the wheel bearings, so first of all, you should adjust this clearance. If this does not help, replace the brake disc.
7. Position the wheels so that the markings applied before removing them match. Screw the wheels on. Remove the car from the stands and tighten the wheel bolts in a cross pattern to a torque of 110 N·m.