What is the function of the wheel cylinder in the braking system?

The function of the wheel cylinder in the braking system is to convert hydraulic pressure to mechanical force. When the brake pedal is pressed, hydraulic fluid is sent through the brake lines to the wheel cylinder. Inside the wheel cylinder, this hydraulic pressure causes the pistons to move outward, forcing the brake shoes against the brake drum (or rotor in disc brake systems). This mechanical action creates friction, which slows down or stops the vehicle.

Understanding this function is crucial because it highlights the importance of hydraulic pressure in modern braking systems, allowing for effective braking with minimal effort from the driver. Other components in the braking system, while essential, do not perform this specific function of transforming hydraulic pressure into the force needed to engage the brakes.