By using visual and percussion methods, the brake shoes and their friction plates should be free of cracks. The brake shoes should be inspected according to the sample plate. If they are bent, twisted, or deformed slightly, they can be corrected by cold pressing. Use a vernier caliper depth gauge to measure the distance between the rivet head of the friction plate and the surface of the friction plate, which should not be less than 0.80mm. The thickness of the lining should not be less than 9mm. Otherwise, replace it with a new lining or brake shoe assembly. If the friction plate has light oil stains and only a small amount of wear on the lining, gasoline can be used to clean the oil stains. After cleaning, it must be heated and dried, and then smoothed with a file and coarse sandcloth. The fitting area should be measured with the brake drum surface, and it must meet technical standards. It is allowed to continue using.