CDL · Doubles and triples
What is the reason for moving a dolly clear of the rear trailer before releasing it from the lead trailer?
Correct answer: Because unlocking the pintle hook while the dolly is still under the trailer can make the tow bar fly up, hurting someone and making recoupling hard.
Answer options
- ABecause unlocking the pintle hook while the dolly is still under the trailer can make the tow bar fly up, hurting someone and making recoupling hard Correct
- BBecause getting the dolly out of the way first lets you crank the landing gear down sooner, which cuts the total time the uncoupling takes
- CBecause a dolly left under the trailer puts extra strain on the fifth-wheel locking jaws and makes them wear out faster
Why
If the dolly is still under the rear semitrailer when you unlock the pintle hook, the tow bar can snap upward. That can injure you and makes the dolly very hard to hook up again.
About this question
Topic: Doubles and triples License: CDL
Part of these practice sets:
Where it applies: Asked in every state.
Practice the whole set
This question is part of Coupling Doubles and Converter Dollies (28 questions). Take the full set and check your score.
Practice Coupling Doubles and Converter DolliesMore questions from Coupling Doubles and Converter Dollies
- What should you use to hold the second trailer still before you couple it to the rest of the doubles combination?
- Which statement about converter dollies is accurate?
- Compared with an A-dolly, what is the main thing a B-dolly or C-dolly adds?
- The dolly is now hitched behind the first trailer, and the second trailer sits on the dolly's fifth wheel. What is the proper way to test this coupling?
- In the official CDL manual, the section on doubles and triples generally explains coupling and uncoupling for which combinations?
- Uncoupling a set of triples starts with which step?
- When you drop the rear trailer from a double combination, what should you do with the air shut-off valve at the back of the front trailer?
- Which description fits a converter dolly?
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