What component is responsible for the force amplification in a hydraulic brake system?

The component responsible for force amplification in a hydraulic brake system is the brake booster. The brake booster utilizes engine vacuum or hydraulic pressure to enhance the force applied to the brake pedal, allowing the driver to exert less physical effort while achieving the desired braking force. This is particularly important in vehicles, as it ensures a more responsive braking action without requiring the driver to apply excessive force.

In contrast, while the brake pedal is where the driver initiates the braking action, it does not amplify the force; instead, it simply transfers the force applied by the driver. Hydraulic fluid is essential for transferring the force throughout the braking system, but it does not amplify the force itself. The brake rotor is a crucial component in the braking mechanism, providing the surface against which brake pads press to create friction, yet it does not play a role in force amplification.