Coupling & UncouplingQuestion 13 of 60
When uncoupling, what does pulling the fifth wheel release handle to the open position do?
a.Unlocks the fifth wheel locking jaws so the kingpin can slide out
b.Raises the landing gear
c.Supplies air to the trailer
d.Locks the trailer brakes
Explanation
Pulling the release handle to the open position unlocks the fifth wheel jaws so the trailer kingpin can separate as the tractor pulls forward. You should only do this after the landing gear supports the trailer and the trailer brakes are set. Chock the wheels if the trailer has no spring brakes.
Practice all 60 questions free — no signup required.
Related questions on this topic
- When you push the trailer air supply valve in (supply air to trailer), what should happen?
- During uncoupling, when should you lower the landing gear?
- What should you do with the air lines and electrical cord before pulling the tractor away from the trailer during uncoupling?
- After unlocking the fifth wheel jaws during uncoupling, how should you move the tractor?
- Why is it important that the kingpin be properly locked, not just resting on the closed fifth wheel jaws?
- When raising the landing gear after coupling, what should you be aware of regarding the crank handle?
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against CDL Combination Vehicles Knowledge Test · How we review