During the final air brake check, which condition indicates a potential problem?

• A. Air pressure does not build up quickly
• B. The engine stalls
• C. The vehicle drifts to the left
• D. The cabin lights dim

Answer: (A)

During the final air brake check, the air pressure should rise promptly to the governor setting. If it does not build up quickly, it signals a potential problem such as a leak, a failing compressor, or another fault in the air system that could prevent brakes from applying or releasing properly. Quick pressure buildup shows the system is sealing and delivering air as needed. Points like the engine stalling, the vehicle pulling to one side, or lights dimming involve other subsystems (engine, steering, electrical) and don’t specifically indicate the air brake readiness being tested.