Uneven wear of brake shoes is a common fault of North American heavy-duty trucks, which will lead to unbalanced braking force, vehicle offset during braking, shortened part service life and even DOT inspection failure. The main causes are summarized into four points. First, slack adjuster failure: stuck or inflexible adjusters cause inconsistent opening degrees of left and right brake shoes, resulting in asymmetric wear. Second, brake drum deformation: long-term high-temperature braking causes drum bending and scoring, making partial friction of brake shoes excessive. Third, repair kit accessory aging: loose springs and worn pins lead to inconsistent reset of brake shoes. Fourth, improper installation: non-standard installation angle and offset assembly cause partial wear. The corresponding solutions are regular inspection and lubrication of slack adjusters, timely replacement of deformed brake drums, synchronous update of repair kit accessories when replacing brake shoes, and standardized installation in strict accordance with truck model parameters. Solving uneven wear can maximize the service life of brake shoes and ensure stable braking performance.
