Air brake systems combine which three different systems?

The correct answer identifies the three key components that make up air brake systems: service brakes, parking brakes, and emergency brakes.

Service brakes are the primary means of stopping the vehicle while driving, activated by the driver’s foot. They are essential for normal vehicle operation. The parking brake, on the other hand, secures the vehicle when it is parked and prevents rolling when parked on an incline or decline. Lastly, emergency brakes serve as a backup system that can be used when the service brakes fail; they are designed to bring the vehicle to a stop in case of an emergency.

Together, these three braking systems work in concert to ensure vehicle safety and control, highlighting the importance of understanding how they function in different scenarios.