- Entry Level Driver Training Coupling and Uncoupling Questions and Answers Flashcards

When coupling a tractor to a trailer, what should you check before backing under the trailer?

Answer: That the kingpin is not bent or broken

A bent or broken kingpin will not lock properly in the fifth wheel, creating an extremely dangerous situation where the trailer could separate from the tractor.

After coupling, how do you test that the fifth wheel is securely locked?

Answer: Apply the trailer brakes and pull forward gently

The tug test involves applying the trailer brakes and gently pulling forward in low gear to verify the fifth wheel jaws are locked around the kingpin.

What is the correct height for the trailer when coupling?

Answer: The trailer should be slightly lower than the fifth wheel

The trailer nose should be slightly lower than the fifth wheel so that it is raised by the fifth wheel during coupling, ensuring the kingpin engages properly.

During uncoupling, when should you lower the landing gear?

Answer: Before disconnecting the air lines and pulling the release handle

Landing gear must be lowered before disconnecting anything to support the trailer's weight and prevent it from tipping or falling when separated from the tractor.

What should you do if the fifth wheel release handle is hard to pull during uncoupling?

Answer: Back up slightly to relieve pressure on the kingpin

Backing up slightly shifts the weight off the locking jaws, relieving pressure on the kingpin and making the release handle easier to operate.

What is the purpose of the glad hands in the coupling process?

Answer: They connect the air lines between tractor and trailer

Glad hands are the coupling devices used to connect the air brake hoses between the tractor and trailer, allowing the tractor to supply air pressure to the trailer braking system.