Control & OperationCâu 72 / 120
You are uncoupling a trailer in a yard. Which sequence is correct?
a.Pull the fifth wheel release, then lower the landing gear, then chock the wheels
b.Disconnect the air lines first, then pull forward, then lower the landing gear
c.Ease pressure on the locking jaws, chock the trailer wheels, lower the landing gear until it takes the weight, disconnect the air and electrical lines and secure them, pull the release handle, and pull the tractor partially clear before checking
d.Lower the landing gear, pull completely clear, then disconnect the lines
Giải thích
Taking pressure off the jaws, securing the trailer, setting the landing gear, and only then releasing and easing forward keeps the trailer supported at every step. The other sequences release the coupling or the lines before the trailer is supported, which can drop the trailer or tear the air lines apart.
Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- What is off-tracking, and why does it matter in turns?
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- Before backing under a trailer, how should the trailer height be set?
- 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?
- You are on a slick, snow-covered road descending a grade. What should you do with the engine brake or retarder?
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