What component converts hydraulic pressure from the master cylinder to mechanical force?

The correct choice, the wheel cylinder, plays a crucial role in the hydraulic braking system of a vehicle. When the driver presses the brake pedal, hydraulic pressure is generated in the master cylinder and transmitted through the brake lines to the wheel cylinders located at each wheel. The wheel cylinder then converts this hydraulic pressure into mechanical force.

This mechanical force pushes the pistons in the wheel cylinder outward, which in turn forces the brake shoes against the brake drum, or in the case of disc brakes, the caliper squeezes the brake pads against the rotor. This action creates the friction necessary to slow down or stop the vehicle.

In contrast, the brake rotor is a component that rotates with the wheel and serves as a surface for the brake pads to clamp onto, but it does not convert hydraulic pressure to mechanical force. The caliper contains the wheel cylinder mechanisms but is not itself the component that directly converts hydraulic pressure. The brake shoe works with the drum brakes but also doesn't perform the function of converting hydraulic pressure. Instead, it's the wheel cylinder specifically that completes this essential function in the braking process.