Arizona Air Brakes CDL Practice Test

What is the maximum allowable leak rate for an air brake system when the engine is off?

1. 4 PSI per minute

2. 3 PSI per minute

3. 2 PSI per minute

4. 1 PSI per minute

The correct answer is: 2 PSI per minute

The maximum allowable leak rate for an air brake system when the engine is off is indeed 2 PSI per minute. This standard is critical for ensuring the safety and reliability of air brake systems in commercial vehicles. A leak rate greater than this indicates potential issues within the brake system that could lead to failure or reduced braking efficiency. Maintaining a leak rate within this limit ensures that there is enough air pressure available for safe operation of the brakes when the vehicle is in use. If the leak rate is higher, it may suggest that components such as valves, fittings, or hoses are not sealing properly, which could compromise the brake system's effectiveness in an emergency situation. Understanding this parameter is essential for drivers and technicians, as regular checks against this standard help in the early detection of possible faults within the braking system, promoting both compliance with safety regulations and the overall safety of vehicle operation on the road.