Practice question

During New Jersey CDL air-brake preparation, what is the proper way to confirm the trailer parking (spring) brakes work?

Connect a fully charged trailer, release tractor parking brake, pull the red trailer air supply knob OUT, and gently try to move the rig forward in a low gear — it should hold
Apply only the foot brake
Drain the trailer tanks
Disconnect the glad hands

Answer: A — Connect a fully charged trailer, release tractor parking brake, pull the red trailer air supply knob OUT, and gently try to move the rig forward in a low gear — it should hold

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