Home › CDL Practice Tests › Combination Vehicles Questions › Question 6
What does a tug test check after coupling?
- A.Whether the fifth wheel locking jaws are actually holding the kingpin when the tractor pulls gently against the trailer brakes
- B.Whether the trailer tires are properly inflated
- C.Whether the electrical lights are bright enough
- D.Whether the landing gear crank works smoothly
Correct answer
A. Whether the fifth wheel locking jaws are actually holding the kingpin when the tractor pulls gently against the trailer brakes
Why
With the trailer brakes set, a gentle pull in a low gear loads the connection without driving away. If the jaws are not locked, the tractor will separate here at low speed instead of on the road.
Manual topic: Combination Vehicles - Coupling · From the Combination Vehicles practice bank (CV-006).