Brake pads can directly reflect the braking effect, so brake pads are the most critical and direct components in the automotive braking system. The brake pad is usually made up of the floor, the adhesive insulation layer and the friction layer. The heat insulation layer of the brake disc is made up of the bad conduction material and the reinforced material. The friction layer of the brake disc is made up of reinforced materials, adhesives and fillers. Generally, the hydraulic transmission is applied to the piston of the brake caliper to push the brake pad and brake disc or drum contact friction into heat energy, so as to achieve the role of deceleration and braking. The best time to replace the brake disc, the thickness of the brake disc of the disc brake can be checked by the method of the brake plate, and the brake shoe thickness of the drum brake shoe should be pulled out from the brake. However, whether the brake pad on the disc brake or the brake disc on the drum brake, the manufacturer stipulates that the thickness should not be less than 1.2mm because, through all actual measurements, the brake disc is worn and peeled faster before or after the 1.2mm. Therefore, the car owner should check and replace the brake disc at this time or before, the general vehicle, in the normal driving condition, the brake disc of the front brake is 3 - 50 thousand kilometers, and the service life of the brake disc of the rear brake is 12 - 150 thousand kilometers. First, check whether the brake disc is pure accessories, the integrity of the product packaging, anti counterfeiting signs and packaging logo and the logo on the brake disc are consistent, the product model is consistent with the content of the certificate. Before lifting the vehicle, the covering of the brake oil should be opened first, and the tyre bolts should be loosened diagonally. If a simple jack is used to support the jack, the jack should be secured and the wheel without replacing the brake pad should be reinforced. Unload the tyre, loosen the fastening screws of the clamp body, check the screws and the slider guide bar, remove the sediment and oil pollution above, and maintain the lubricating oil. Remove the old brake pad, check the wear degree of the brake disc, and start the ditches. A new brake disc should be replaced with a new brake disc with a period of 8 to 120 thousand kilometers, otherwise the wear of the newly replaced brake disc will be accelerated, and the direction jitter of the brake should be made. The new brake pad should be divided into the inside and outside, and the friction surface of the brake disc should be made to the brake disc so that the disc will fit properly. Fasten the attachments and fasten the pliers. Before fastening the clamp body, the stopper on the clamp is pushed back to the position by means of tools, so that the clamp can be installed in place. If the brake pad on drum brake needs to be replaced, it is suggested that professionals should be operated to avoid mistakes. After installing the brake, the tire should be reset. When installing the tyre screws, the corners should be fastened, so that the tire and brake hub can be protected. At the same time, it is also necessary to check whether the wear of the tread and edge is normal. It is best to replace the left and right two wheels regularly, which will help to prolong the service life of the tire. Finally, you need to check the brake fluid. The brake fluid should be replaced regularly and added. At the same time, the brand name of the brake fluid should be consistent with the brand name of the original brake fluid. This will help to clear the dirt in the brake pipeline and be more sensitive to the brake. If the brake fluid of different brands is used mixed, chemical changes will occur, and the sludge and the inorganic salt are deposited in the brake system. The daily product of the brake fluid will block the pipeline, causing the brake failure, and the consequences are unimaginable. Before driving out of position, apply force air to the brakes until you feel that the brake has been returned to the ideal position of steady state.