To uncouple ground air lines from equipment, what should you do first if equipped?

To uncouple ground air lines from equipment, what should you do first if equipped?

• A. Operate the bleed valve on the ground air to release the pressure
• B. Open the angle cock on the equipment
• C. Disconnect the ground air hose
• D. Inspect the coupling for signs of wear

Answer: (A)

Relieve the pressure first by operating the bleed valve on the ground air line. Ground air is under significant pressure, and disconnecting while it’s still charged can cause a sudden air release that could injure you or affect the braking system. Bleeding the line brings it to a safe pressure, after which you can proceed with isolating and disconnecting. The other steps—such as closing the angle cock, then disconnecting, and finally inspecting the coupling—come after depressurizing.

Relieve the pressure first by operating the bleed valve on the ground air line. Ground air is under significant pressure, and disconnecting while it’s still charged can cause a sudden air release that could injure you or affect the braking system. Bleeding the line brings it to a safe pressure, after which you can proceed with isolating and disconnecting. The other steps—such as closing the angle cock, then disconnecting, and finally inspecting the coupling—come after depressurizing.