ELDT Coupling and Uncoupling 3 — Questions and Answers
Question 1: Before uncoupling, why should you lower the landing gear until it makes firm contact with the ground?
- To lift the trailer off the fifth wheel
- To support the trailer weight once the tractor pulls out (Correct answer)
- To level the tractor cab
- To charge the trailer air tanks
Correct answer: To support the trailer weight once the tractor pulls out
The landing gear must firmly support the trailer so it does not drop when the tractor is removed.
Question 2: When lowering the landing gear, why avoid raising the trailer off the fifth wheel too much?
- It wastes air pressure
- It makes recoupling difficult and can damage the gear (Correct answer)
- It locks the kingpin
- It drains the battery
Correct answer: It makes recoupling difficult and can damage the gear
Raising the trailer too high strains the landing gear and complicates recoupling later.
Question 3: What is the proper order for the fifth wheel release before pulling the tractor out?
- Pull the release handle to open the jaws (Correct answer)
- Push the trailer forward
- Raise the landing gear
- Disconnect the electrical cable only
Correct answer: Pull the release handle to open the jaws
You must pull the fifth wheel release handle to unlock the jaws before the tractor can pull free of the kingpin.
Question 4: After disconnecting the air lines during uncoupling, what should you do with them?
- Leave them hanging on the ground
- Secure them to prevent damage and dirt (Correct answer)
- Cut off the glad hands
- Tie them to the trailer brakes
Correct answer: Secure them to prevent damage and dirt
Store or hang the air lines on the dummy couplers so they stay clean and undamaged.
Question 5: When easing the tractor forward to clear the fifth wheel from under the trailer, you should:
- Accelerate quickly to break free
- Pull out slowly and smoothly (Correct answer)
- Reverse hard first
- Rev the engine and release the clutch fast
Correct answer: Pull out slowly and smoothly
Pulling forward slowly prevents jerking the trailer or damaging the landing gear.
Question 6: Before uncoupling, you should chock the trailer wheels when:
- The trailer has working spring brakes and air
- The trailer has no air supply or its brakes may not hold (Correct answer)
- It is always unnecessary
- Only in freezing weather
Correct answer: The trailer has no air supply or its brakes may not hold
Chock the trailer wheels if the trailer lacks air pressure or its spring brakes may not hold it in place.
Question 7: What should the ground surface be like before lowering landing gear to uncouple?
- Soft mud so the gear sinks in
- Firm and level so the trailer stays stable (Correct answer)
- Steeply sloped
- Covered in loose gravel piles
Correct answer: Firm and level so the trailer stays stable
Uncouple on firm, level ground so the landing gear supports the trailer safely without sinking or tipping.
ELDT Coupling and Uncoupling 3
Before uncoupling, why should you lower the landing gear until it makes firm contact with the ground?