cat ironing board cover_front door washing machine cover
Another essential part of the drum brake system is the wheel cylinder. Located at the top of the brake assembly, it houses pistons that are activated when hydraulic pressure from the brake fluid is applied. The wheel cylinder pushes the brake shoes outward, creating friction against the drum. This hydraulic mechanism allows for smooth and powerful braking with minimal effort from the driver.
components of a drum brake

The wheel cylinder is central to the operation of drum brakes. It contains two pistons—one for each brake shoe. As hydraulic fluid enters the expanded wheel cylinder, it pushes the pistons outward, causing the shoes to press against the drum. Understanding this mechanism is crucial for diagnosing problems; if one side of the cylinder fails, it can lead to uneven braking and potential safety hazards.
drum brake line diagram
