What is the primary purpose of the brake booster?

The primary purpose of the brake booster is to assist in applying pedal force. A brake booster is designed to amplify the force that the driver applies to the brake pedal, making it easier to engage the brakes. This is particularly important because braking requires significant force to effectively slow down or stop a vehicle. The brake booster typically uses vacuum pressure from the engine (in vacuum-assisted systems) to enhance the effort applied by the driver, allowing for a smoother and more effective braking experience without requiring excessive force on the pedal.

In this context, while maintaining hydraulic pressure and providing vacuum may be functions associated with different aspects of the braking system, they do not specifically address the role of the brake booster in enhancing driver input. The pedal feel may be affected by the booster, but the main focus of a brake booster is indeed to provide additional assistance in applying the pedal force.