CDL · Combination vehicles
The fifth wheel jaws have closed on the kingpin, but the locking lever is not in the locked position. What does this tell you?
Correct answer: The coupling is faulty and must be fixed before you drive.
Answer options
- AYou may now slide the fifth wheel to adjust weight balance
- BThe coupling is faulty and must be fixed before you drive Correct
- CThe parking lock is disengaged, so you are free to leave
Why
If the lever stays unlocked, the jaws may not be holding the kingpin securely, and the trailer could break away once the rig is moving. Do not drive until the coupling has been corrected.
About this question
Topic: Combination vehicles License: CDL
Part of these practice sets:
Where it applies: Asked in every state.
Practice the whole set
This question is part of Trailer Air Lines and Coupling (28 questions). Take the full set and check your score.
Practice Trailer Air Lines and CouplingMore questions from Trailer Air Lines and Coupling
- How do you test whether the tractor and semitrailer are securely coupled?
- When you look over a fifth-wheel coupling after hooking up, what should you see?
- When you park a tank trailer, what should hold it in place?
- For a secure coupling, the fifth wheel jaws must grip which section of the kingpin?
- You have just charged the trailer's air system. How do you verify that the lines were not crossed and that the trailer brakes respond?
- How should you position the tractor as you prepare to back under a semitrailer?
- When the trailer air supply knob is pushed in, what does it do?
- While your combination vehicle is moving, its service air line pulls apart, yet the emergency line holds. What is the immediate effect?
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