Control & OperationCâu 71 / 120
Before backing under a trailer, how should the trailer height be set?
a.Slightly lower than the center of the fifth wheel so the trailer is lifted a little as the tractor backs under
b.High enough that the fifth wheel passes underneath without touching
c.Exactly level with the top of the fifth wheel
d.As high as the landing gear will go
Giải thích
A trailer set slightly low is raised as the tractor backs under, which ensures the kingpin engages the jaws properly. A trailer that is too high lets the tractor slide under without coupling or strikes the nose, and exactly level or fully raised risks a missed or damaged coupling.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- You are making a tight right turn at an intersection in a tractor-trailer. What is the correct technique?
- What is off-tracking, and why does it matter in turns?
- You are coupling a tractor to a trailer. Which step comes immediately before backing under the trailer?
- You are uncoupling a trailer in a yard. Which sequence is correct?
- After uncoupling, you notice the landing gear crank handle is left extended. Why must it be secured?
- You are parking on a slight grade and will leave the vehicle. What should you do?
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