Brake Drum: Testing and Inspection

Clean and inspect the brake drum any time the brake drum is removed. Check the brake drum for the following conditions:
^ Cracks
^ Scores
^ Deep grooves
^ Out-of-round

SURFACE FINISH
^ Inspect the brake linings every 10000 km (6,000 miles) and any time the wheels are removed.
^ Replace bonded brake shoe and lining assemblies when the thickness of any lining is worn within 0.76 mm (0.030 inch) of the shoe.
^ Replace riveted shoe and lining assemblies when the thickness of any lining is worn within 0.76 mm (0.030 inch) of any rivet head.
^ Always replace disc brake shoe and lining assemblies as a complete axle set.

INSIDE DIAMETER CHECK
Measure the inside diameter of the brake drum at two or more places around the circumference of the braking surface. Measure at the same distance in from the edge of the drum. Compare the results with the wear specifications. Refer to Component Specifications.

TAPER CHECK
Check the drum taper by measuring at the inner and outer edges of the machined surface. Measure at two or more places around the drum.