Arizona Air Brakes CDL Practice Test

In a single vehicle with a fully charged air system, what is the maximum acceptable air pressure loss after a brake is applied?

1. 2 psi per minute

2. 3 psi per minute

3. 4 psi per minute

4. None of the above

The correct answer is: 3 psi per minute

The maximum acceptable air pressure loss after a brake is applied in a single vehicle with a fully charged air system is indeed 3 psi per minute. This standard is crucial for ensuring that the air braking system is functioning properly, as it indicates the system's ability to hold pressure and respond effectively to braking needs. Understanding how air brakes work is essential for safe vehicle operation. When the brake pedal is pressed, air is directed to the brake chambers, which then apply the brakes. If there is too much pressure loss when brakes are applied, it could signify air leaks or other issues in the system that might lead to brake failure or reduced braking efficiency. Maintaining an air pressure loss at or below this threshold helps ensure that the braking system remains reliable and that the vehicle can stop in a safe and controlled manner. This limit serves as a baseline for inspection and maintenance practices, ensuring that any deviations can be identified and addressed promptly.