Are you dealing with Bendix or Huck brakes? Hucks have a cup shaped adjuster on each end of the wheel cylinder, while Bendix brakes have a single adjuster at the bottom that bridges the gap between the shoes. It's not uncommon for a Huck brake to wear only one lining while the other one on the same wheel looks brand new. Bendix brakes are self-energizing, meaning that the rotation of the drum forces the shoe assembly toward the rear, wearing the longer rear lining a bit more than the short one in front. Huck brakes should have the same length linings front and rear, although some rebuilders used the wrong linings on the Huck shoes.
Brake adjustment does not affect the wear rate of the linings- - - -the only thing an out of adjustment brake will cause is a low pedal and/or the necessity to pump the brakes to get any stopping effect. It would take a restricted brake line or a plugged up flex line to keep the rear brakes from wearing.
Jerry
