Attention! If one brake disc needs to be replaced, replace both to ensure uniform braking. When replacing the brake discs, also replace the brake pads.
Examination
Apply the parking brake and chock the rear wheels.
Loosen the front wheel nuts. Raise the front of the car and place it on stands. Remove the front wheel. Screw the wheel nuts onto the studs, placing thick washers under them to secure the disc during the test.
Pic. 11.20. Arrangement of bolts of fastening of a bracket of a support of a forward brake to a rotary fist
Remove the front brake caliper without disconnecting the brake hose from it. Tie the caliper to the A-pillar using soft wire. Remove the two bolts securing the caliper bracket to the steering knuckle (pic. 11.20). Don't lose the brake shoe guides.
Slowly rotating the brake disc, visually check its condition on both sides. Brake disc wear from pads must be within acceptable limits. If there are cracks on the disc, the disc must be replaced.
Pic. 11.21. Checking brake disc runout
Use a dial indicator to check the runout of the brake disc. Fix the dial indicator in any convenient place and, by rotating the brake disc, determine its runout at a distance of 12 mm from the outer edge (pic. 11.21). Before checking brake disc runout, make sure the hub bearing is in good condition.
Check the brake disc for cracks, especially around the wheel bolt holes, and for excessive wear or mechanical damage. If you need to replace at least one of the disks, replace both disks on the axle.
Pic. 11.22. Measuring the thickness of a brake disc using a micrometer
Measure the brake disc thickness (pic. 11.22). The value of the minimum allowable brake disc thickness is stamped on the inside of the disc. It is recommended to use a micrometer to measure the thickness of the brake disc.
Removing
Loosen the wheel nuts with thick washers that were installed to check the runout of the disc. Remove the brake disc
Installation
Install the brake disc onto the wheel studs.
Install the caliper bracket to the steering knuckle and secure with bolts. Install the support.
Install the wheels and lower the vehicle to the ground.
Press the brake pedal several times to bring the brake pads into position.