If air pressure does NOT build up to normal within the correct amount of time:

If air pressure does NOT build up to normal within the correct amount of time:

• A. your air pressure may drop too low while driving, requiring an emergency stop
• B. the brakes will stop functioning permanently
• C. your tires will overheat
• D. the steering wheel will lock

Answer: (A)

Air brake systems rely on stored compressed air to apply the brakes, and they must reach normal operating pressure quickly after the engine starts. If that pressure does not rise to the required level within the expected time, braking power can be reduced or lost while you’re driving. In that situation, the safest course is to stop as soon as you can safely do so and inspect the system for leaks, a faulty compressor, or other issues before continuing. This is why the best choice describes air pressure dropping too low during operation and the need for an emergency stop to address the problem. The other options aren’t aligned with how air brakes function: a failure to build pressure isn’t typically a permanent brake failure, it doesn’t directly cause tires to overheat, and it doesn’t cause the steering wheel to lock.