Inspection of brake pads and parking brake shoes
1. Raise and secure the vehicle.
2. Remove the rear wheels. Follow section 2E, Tires and Wheels.
3. Perform an external inspection of the brake shoe and parking brake shoe for minimum thickness and wear.
4. Measure the thickness of the pads. See "General technical characteristics" in this section.
5. The brake pads should be changed as a set on both wheels of the axle.
5. The brake pads should be changed as a set on both wheels of the axle.
6. Install the rear wheels. Follow section 2E, Tires and Wheels.
7. Lower the car.
Inspection of the rotor
Brake discs are manufactured to tight tolerances for thickness, flatness and axial runout, but during use, pitting corrosion and grooves appear on the discs. Unacceptable deviations in the shape of the disc brake surfaces can lead to ineffective braking and pedal pulsation when braking. The roughness of the disc surface is also important, since its deviation from the required values can lead to the car being pulled to the side when braking and to rapid wear of the linings. If the disc does not meet technical requirements, it must be ground or replaced. Disc grinding should only be done on precision equipment.
The thickness of the brake disc is checked by measuring at least four places around the circumference of the disc. All measurements must be taken at the same distance from the edge of the disc. If the obtained values of the disc thickness differ from each other by more than 1.0 mm (0.04 inches), this may cause pulsation of the brake pedal and/or vibration of the front of the car when braking. The thickness can be measured with a regular micrometer and should not be less than 20 mm (0.79 inches).
Minor scuffs on the disc surface, the depth of which does not exceed 0.40 mm (0.016 mm), are allowed. The depth of the scuffs can be measured using a standard brake micrometer.
The maximum permissible lateral runout is 0.04 mm (0.001 inches). If the lateral runout is higher than specified, make sure there is no dirt between the disc and the hub, as well as no burrs or scratches on their contact surfaces. Check the axial runout of the disc using a standard indicator in the manner specified below.
1. Place the gear shift lever in neutral (NEUTRAL) and raise the vehicle.
2. To maintain wheel balance, mark the position of the wheel and hub relative to each other. Remove the rear wheel.
3. Secure the brake disc to the wheel hub.
4. Install the dial indicator on the caliper.
5. Set the indicator probe at a distance of about 10 mm (0.39 inches) from the outer edge of the disk at a right angle to its surface and with a slight pressure. While rotating the disk, watch the indicator readings.
6. After completing the measurements, remove the indicator and wheel nuts.
7. If necessary, grind the disc on precision equipment. After grinding, it is necessary to measure the runout again. If the runout after grinding exceeds 0.04 mm (0.001 inches), then the brake disc should be replaced.
8. Align the marks that were made before removing the wheel and install the rear wheel.
9. Lower the car.
[Information taken from the official website: ChevyMan.ru]