Remove the wheel from the drum, and remove the drum. Refer to Section 06-02.
Removal of dust and dirt from brake assemblies should be done by using the
Rotunda Brake Vacuum 091-00001 or Rotunda Brake Parts Washer 065-00016 or
equivalent.
Inspect the brake shoes for excessive lining wear or shoe damage. If the
lining is worn within 0.8mm (1/32 inch) of the rivet heads or 1.5mm (1/16 inch)
of the shoe on bonded linings, or if the shoes are damaged, they must be
replaced. Replace any lining that has been contaminated with oil, grease, or
brake fluid. Replace lining in axle sets. Prior to replacement of lining, the
drum diameter should be checked to determine that the brake drum braking
surface diameter is within specification by using the Rotunda Brake Drum
Micrometer 010-00010 or equivalent. If the braking surface diameter exceeds
specification, the drum must be replaced.
Check the condition of brake shoes, retracting springs, hold-down springs,
and drum for signs of overheating. If the shoes have a slight blue coloring,
indicating overheating, the retracting and hold-down springs should be
replaced. Overheated springs lose their pull 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.
Inspect all other brake parts, and replace any that are worn or damaged.
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 drum is exceeded
either by wear or refinishing, the drum must be replaced. Refer to Section 06-02 for refinishing.
