Brake Shoe: Testing and Inspection

Inspect brake shoe and linings for peeling, cracking, or extremely uneven wear on the lining. Also, inspect the lining for normal wear. If the lining material is less than 1 mm (0.039 inch), the rear brake shoes and linings must be replaced. Replace any brake shoe and lining that has been contaminated with oil, grease or brake fluid. Replace brake shoe and lining in axle sets only. Never replace just one shoe of a brake assembly. Replace both leading and trailing shoes. Prior to replacement of lining, check drum diameter to determine that brake drum diameter is within specification. If braking surface diameter exceeds specification, brake drum must be replaced.

Check condition of brake shoe adjusting screw spring, brake shoe hold-down spring and brake drum for signs of overheating. If brake shoe and lining have a slight blue coloring, indicating overheating, brake shoe adjusting screw springs and brake shoe hold-down springs should be replaced. If not replaced, overheated springs lose their tension and could allow new lining to drag and wear prematurely.