Unequal lining wear between the leading and trailing end of a shoe indicates what?

Unequal lining wear between the leading and trailing end of a brake shoe typically points to issues with the return spring. When the return spring is weak or failing, it may not effectively pull the brake shoe back into its resting position after braking. This results in the leading edge of the brake shoe being applied more heavily and wearing down faster compared to the trailing edge.

Consistent and adequate spring tension is crucial for the proper functioning of drum brakes because it ensures that the shoes retract fully after application, providing even contact with the drum surface. If the return spring does not perform this function adequately, it negatively affects the wear patterns on the brake lining.

In contrast, the other options either do not address the specific issue of uneven wear between the leading and trailing edges or pertain to different aspects of brake performance. Maladjusted brake actuators can cause various braking issues but typically don’t lead to this specific type of wear pattern. An improperly sized brake drum would more likely cause overall brake performance problems, while a defective brake line would affect hydraulic pressure in a disc brake system rather than the wear pattern in a drum brake lining.