Brake shoes carry the brake lining inside brake drum systems. They are a curved piece of metal, with a friction material fixed to one side.
When the driver applies the brake, a wheel cylinder in the drum brake system forces the brake shoe outward, against the inside of the drum. This creates friction between the lining and drum, causing the car to brake. The kinetic energy is dissipated as heat. Brake shoes are often used for the rear axle, especially as most modern cars brake more sharply on their front wheels, so the temperatures the rear brakes need to handle aren’t so high. As well as being less expensive to manufacture, drum brake systems can be more effective as a parking brake than disc brakes.
The main differences between brake pads and brake shoes are:
Positioning
Brake pads and brake shoes are positioned differently in their braking system. Brake pads are placed inside a caliper which surrounds the brake disc and brake shoes are placed inside the brake drum.
Wear
Brake shoes typically last much longer than brake pads. Usually they are positioned on the rear axle and undertake a much lower proportion of the braking work.