The service brake system:

Question

Air brakes consists of three separate braking systems: the service brake system, the parking brake system, and the emergency brake system. The service brake system applies and releases the brakes when you use the brake pedal while driving normally.

Accepted Answer

Applies and releases the brakes when you press the brake pedal while driving normally.

Answer

Applies and releases the parking brakes.

Answer

Applies and releases the emergency brake.

Answer

Applies and releases the axle brake.