Drum Brake System: Testing and Inspection

1. Raise and support vehicle.
2. Remove the rear wheels and remove the drums.
3. Remove dust and dirt from brake drum assemblies by using the Rotunda Brake/Clutch/Service Vacuum or Rotunda Brake Parts Washer or equivalents.
4. Inspect the rear brake shoes and linings for excessive lining wear or shoe damage. Testing and Inspection

NOTE: Replace lining in axle sets.

^ If the lining is worn within 0.8 mm (1/32 inch) of the rivet heads or 1.5 mm (1/16 inch) of the shoe on bonded linings they must be replaced.
^ If the shoes are damaged, they must be replaced.
^ Replace any lining that has been contaminated with oil, grease or brake fluid.

5. Inspect the brake drum and if necessary, refinish. The maximum inside braking surface diameter is shown on each brake drum. If the maximum inside braking surface diameter shown on the brake drum is exceeded either by wear or refinishing, the brake drum must be replaced.
6. Check the condition of rear brake shoe and lining retracting springs, brake shoe hold-down spring and brake drum for signs of overheating. If the brake drum has a slight blue coloring, indicating overheating, the retracting and brake shoe hold-down springs should be replaced. Overheated brake shoe hold-down springs lose their tension and could cause the new lining to wear prematurely if not replaced. If the brake drums are heat-spotted, indicating an overheated condition, they should be replaced.
7. Inspect all other brake parts and replace any that are worn or damaged.
8. Check wheel cylinders for leakage.