Drum brake device (Honda Accord 3)

Drum brakes use two brake shoes mounted on a fixed backing plate. These shoes are contained within a round cast iron drum that rotates with the wheel. The shoes are held in place by springs; this allows them to slide towards the drum during braking, maintaining the alignment of the linings with the drum. The shoes are actuated by a wheel cylinder, which is mounted on top of the backing plate. When the brakes are applied, hydraulic pressure actuates two drive joints in the wheel cylinder. Since these joints bear directly on the tops of the brake shoes, the shoes are moved towards the inside of the drum. After the tops of the shoes are pressed against the drum, the bottoms of the shoes are also brought into contact with the drum by a slight rotation of the entire assembly (known as servo action). When the pressure inside the wheel cylinder decreases, return springs move the shoes away from the drum.

Most modern drum brakes are designed to self-adjust during braking. This system reduces the need for preventative adjustments and keeps the brake and pedal in good working order.