A drum brake does NOT include which of the following components?

In a drum brake system, a caliper is not a component. Drum brakes operate using a different mechanism compared to disc brakes, which utilize calipers. Instead, drum brakes consist of brake shoes, which press against the inner surface of a rotating drum to create friction and slow down the vehicle. The brake linings are attached to the brake shoes and provide the necessary friction material, while the brake backing plate serves as a structural component that supports the other parts of the drum brake system.

Understanding the distinction between the drum brake and disc brake components is key in identifying which parts belong to which system. The absence of a caliper in the drum brake design is a fundamental aspect of its function, emphasizing the differences in braking technology used in vehicles.