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When should you disconnect the air lines and electrical cord during uncoupling?
- A.Before lowering the landing gear
- B.While driving slowly forward
- C.After the tractor has fully left the trailer
- D.After the landing gear is down and supporting the trailer, and secure the lines so they will not be damaged
Correct answer
D. After the landing gear is down and supporting the trailer, and secure the lines so they will not be damaged
Why
Disconnecting after the trailer is supported keeps the trailer brakes available until the trailer is safely standing on its gear. Securing the lines on the tractor prevents them dragging or fouling when you pull clear.
Manual topic: Combination Vehicles - Uncoupling · From the Combination Vehicles practice bank (CV-040).