Examination
1. Raise the front of the vehicle and secure it on stands. Remove the relevant front wheel.
2. Slowly rotate the brake disc so that it can be viewed from both sides. If necessary, remove the brake pads. The wear of the brake disc from the pads should be within the permissible limits. If the wear exceeds the permissible limit or there are cracks on the disc, the disc must be replaced.
3. If necessary, clean the perimeter of the disc from rust and brake dust.
4. Use a dial indicator to check the brake disc runout. Attach the dial indicator to any convenient location and, by rotating the disc, determine its runout at several points from its center. If the disc runout exceeds the permissible limits, the disc must be replaced. However, the disc runout may be caused by a hub bearing failure.
5. To check the runout of the inside of the brake disc, remove the brake disc from the hub, turn it 180°, re-attach it to the hub and use a dial indicator to measure its runout.
6. Check the brake disc for cracks, especially around the wheel bolt holes.
Removal
1. Unscrew the two bolts that secure the caliper to the hub. Remove the caliper and tie it to the front strut using soft wire. Do not deform or stretch the brake hose.
2. Using chalk or paint, mark the position of the brake disc relative to the hub.
3. Remove the screws securing the brake disc to the hub and remove the disc.
Installation
1. Installation is carried out in the reverse order of removal.
2. Please consider the following points:
- check that the working surfaces of the brake disc and hub are clean and not deformed;
- align the marks made earlier, install the brake disc and secure with screws, tightening them to the required torque;
- if a new brake disc is being installed, use a solvent to clean it of its protective grease;
- before tightening the caliper mounting bolts, coat the bolt threads with a lubricant (Loctite Frenetanch);
- install the wheel and lower the car;
- press the brake pedal several times to set the brake pads into working position.