Final answer:
The minimum thickness for brake shoes and linings depends on the vehicle, but generally, brake linings should be replaced at 1/32 to 1/16 inch, and brake shoes at about 1 millimeter.
Step-by-step explanation:
The minimum thickness for brake shoes and linings varies depending on the vehicle make and model, but a general rule is that brake linings should be replaced when they reach approximately 1/32 inch to 1/16 inch of remaining friction material. For brake shoes, a common minimum thickness is roughly 1 millimeter. It's important to consult the vehicle's service manual for the exact specifications because driving with worn brake linings or shoes can significantly reduce braking efficiency and is a serious safety hazard.