Which component helps apply the brake shoe by converting hydraulic pressure?

The wheel cylinder plays a crucial role in the braking system by converting hydraulic pressure into mechanical force that applies the brake shoes. When the brake pedal is pressed, hydraulic fluid is forced into the wheel cylinder. This fluid pressure causes pistons inside the cylinder to move outward. As these pistons extend, they push the brake shoes against the drum or rotor, effectively slowing down or stopping the vehicle.

The wheel cylinder is integral to the functionality of drum brake systems and provides the necessary force to engage the brake shoes. Unlike other components such as the return spring, which is responsible for pulling the brake shoes back after braking, or the adjusting screw, which is used for setting the proper clearance for the brake shoes, the wheel cylinder is specifically designed to act upon hydraulic pressure. Brake pads are part of disc brake systems and do not convert hydraulic pressure; rather, they are the components that create friction against the brake rotor to stop the vehicle. Therefore, the wheel cylinder is the most accurate choice for a component that converts hydraulic pressure into the force applied to the brakes.