- loosen the wheel bolts, raise the corresponding part of the car and fix it on stands;
- remove the wheel;
- remove the brake pads;
- slowly rotate the brake disc so that it can be seen from both sides. 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;
- if necessary, clean the perimeter of the disc from rust and brake dust;
- check brake disc runout with a dial gauge. 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. To check the runout of the inner side of the brake disc, remove the brake disc from the hub, turn it over 180°, re-attach it to the hub and measure its runout with a dial indicator;
- check the brake disc for cracks, especially around the wheel bolt holes;
Pic. 8.15. Bolt location (1) front brake disc mounts (2)
Pic. 8.16. Location of brake pads and bolts (1) rear brake disc mounts (2)
- unscrew bolts 1 and remove brake disc 2 (pic. 8.15, 8.16).
To install a brake disc:
- check the condition and measure the thickness of the brake disc;
- If a brake disc needs to be replaced, both must be replaced to ensure uniform braking. When replacing brake discs, the brake pads must also be replaced;
- check and, if necessary, clean the mating surfaces of the brake disc and hub. When installing a new brake disc, remove a layer of protective coating from its surface;
- install the brake disc on the wheel hub and secure with bolts, tightening them with a torque of 10 Nm;
- install brake pads;
- install the wheel and lower the car to the ground;
- Press the brake pedal hard several times to press the brake pads against the brake disc.