Study for the Air Brake Test. Prepare using flashcards and multiple-choice questions, complete with hints and explanations. Get ready to ace your exam!

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A straight air brake system can't spill more than what psi per minute with the brakes released and the engine off?

  1. 1 psi.

  2. 2 psi.

  3. 3 psi.

  4. 4 psi.

The correct answer is: 2 psi.

In a straight air brake system, it's crucial to monitor air pressure when the brakes are released and the engine is off to ensure proper function. The acceptable loss of air pressure, which is indicated by the allowable psi drop per minute in this scenario, is 2 psi. This standard is in place to confirm that there are no leaks or faults in the system that could compromise braking efficiency. A loss greater than this threshold can indicate a potential issue such as a leak in the brake lines, which could lead to insufficient air pressure when braking is actually needed. Therefore, maintaining a drop of 2 psi or less ensures that the air brake system remains reliable and safe for operation. This standard is a vital part of maintaining the integrity of the air brake system, as it assures drivers that the brakes will respond appropriately when engaged.