In air-braked vehicles, when should the parking brake be used?

In air-braked vehicles, when should the parking brake be used?

• A. Only When the Engine Is On
• B. Any Time the Vehicle Is Parked
• C. When the Vehicle Is Moving
• D. Only On Hills

Answer: (B)

Using the parking brake whenever you park is essential for air-braked vehicles. These systems rely on air pressure to release the service brakes, while a spring mechanism automatically applies the parking brakes when air pressure drops. So when you park and the vehicle is stationary, the parking brake provides a reliable hold even if there are small leaks or the air system loses pressure. That’s why you should apply the parking brake every time you park, whether on a hill or on flat ground. Relying on the engine running, on moving the vehicle, or only using it on hills would not provide a consistent, safe hold when the vehicle is supposed to be stationary.

Using the parking brake whenever you park is essential for air-braked vehicles. These systems rely on air pressure to release the service brakes, while a spring mechanism automatically applies the parking brakes when air pressure drops. So when you park and the vehicle is stationary, the parking brake provides a reliable hold even if there are small leaks or the air system loses pressure. That’s why you should apply the parking brake every time you park, whether on a hill or on flat ground. Relying on the engine running, on moving the vehicle, or only using it on hills would not provide a consistent, safe hold when the vehicle is supposed to be stationary.