How Do Drum Brakes Work
how do drums brake work
Drum brakes are a type of brake system commonly used in older vehicles and some modern applications. They work by using friction created by a set of shoes or pads that press outward against a rotating drum-shaped component. Here's a step-by-step explanation of how they work:
Brake Pedal Pressed
When the driver presses the brake pedal, it pushes a piston in the master cylinder, which sends brake fluid through the brake lines to the wheel cylinders at each wheel.
Wheel Cylinder Activation
The brake fluid reaches the wheel cylinder, located inside the drum brake assembly. The wheel cylinder contains two pistons, one on each side.
Pistons Push Brake Shoes
The hydraulic pressure from the brake fluid pushes the pistons outward. These pistons, in turn, push the brake shoes outward against the inner surface of the brake drum.
Friction Slows the Drum
As the brake shoes press against the drum, the friction between the shoes and the drum slows down the rotation of the drum. Since the drum is attached to the wheel hub, this action slows down or stops the wheel.
Brake Shoes Release
When the driver releases the brake pedal, the hydraulic pressure decreases, allowing return springs to pull the brake shoes back to their original position away from the drum. This releases the friction and allows the drum (and the wheel) to rotate freely again.
Adjuster Mechanism
Drum brakes often include a self-adjusting mechanism to maintain the correct distance between the brake shoes and the drum as the shoes wear down over time. This ensures consistent braking performance.
