Examination
1. Raise the front of the car and secure it on stands. Remove the corresponding front wheel.
2. Slowly turn the brake disc so that it can be seen from both sides. Remove the brake pads if necessary. Brake disc wear from pads must be within acceptable limits. If the wear exceeds the allowable 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 runout of the brake disc. Fasten the dial indicator in any convenient place and, turning the disk, determine its beating at several points from its center. If the beating of the disc exceeds the allowable limits, the disc must be replaced. However, the cause of the disc runout may be the failure of the hub bearing.
5. To check the runout of the inner side of the brake disc, remove the brake disc from the hub, turn it 180°, reattach it to the hub and measure its runout with a dial gauge.
6. Check the brake disc for cracks, especially around the wheel bolt holes.
Removing
1. Unscrew the two bolts securing the caliper to the hub. Remove the caliper and, using a soft wire, tie it to the A-pillar. When doing this, do not deform or stretch the brake hose.
2. Using chalk or paint, mark the position of the brake disc in relation to the hub.
3. Remove the screws securing the brake disc to the hub and remove the disc.
Installation
1. Installation is made in sequence, return to removal.
2. Consider the following points:
- check that the working surfaces of the brake disc and hub are clean and not deformed;
- align the previously made marks, install the brake disc and secure with screws, tightening them to the required torque;
- if a new brake disc is installed, then, using a solvent, clean it of protective grease;
- before screwing the caliper mounting bolts, coat the bolt threads with an anti-screwing agent (Loctite Frenetanch);
- install the wheel and lower the car;
- Depress the brake pedal several times to bring the brake pads into position.