Inspection and defect detection
1. Clean the brake drum thoroughly.
2. Measure the diameter of the drum working surface with a caliper. The maximum permissible drum diameter is 231 mm. If the diameter is greater than the permissible value, the drum must be replaced. If there are marks, the drum can be bored, but taking into account that its final working surface diameter is not greater than the permissible value.
3. The maximum permissible radial runout of the drum, measured on the working surface, is 0.1 mm, and the minimum permissible axial runout is 0.2 mm.