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6.4 – Coupling and Uncoupling (continued)
Step 9: Lock Trailer Brakes
- Pull out the “air supply” knob or move the tractor parking valve control from “normal” to “emergency.”
Step 10: Back Under Trailer
- Use lowest reverse gear.
- Back tractor slowly under trailer to avoid hitting the kingpin too hard.
- Stop when the kingpin is locked into the fifth wheel.
Step 11: Check Connection for Security
- Raise trailer landing gear slightly off ground.
- Pull tractor gently forward while the trailer brakes are still locked to check that the trailer is locked onto the tractor.
Step 12: Secure Vehicle
- Put transmission in neutral.
- Put parking brakes on.
- Shut off engine and take keys with you so someone else does not move truck while you are under it.
Step 13: Inspect Coupling
- Use a flashlight, if necessary.
- Make sure there is no space between upper and lower fifth wheel. If there is space, something is wrong (kingpin may be on top of the closed fifth-wheel jaws, and trailer would come loose very easily).
- Go under trailer and look into the back of the fifth wheel. Make sure the fifth wheel jaws have closed around the shank of the kingpin.
- Check that the locking lever is in the “lock” position.
- Check that the safety latch is in position over locking lever. (On some fifth-wheels, the latch must be put in place by hand.)
- If the coupling is not right, do not drive the coupled unit; get it fixed.
Step 14: Connect the Electrical Cord and Check Air Lines
- Plug the electrical cord into the trailer and fasten the safety latch.
- Check both air lines and electrical line for signs of damage.
- Make sure air and electrical lines will not hit any moving parts of vehicle.
Step 15: Raise Front Trailer Supports (Landing Gear)
- Use low gear range (if so equipped) to begin raising the landing gear. Once free of weight, switch to the high gear range.
- Raise the landing gear all the way up. (Never drive with landing gear only part way up as it may catch on railroad tracks or other things.)
- After raising landing gear, secure the crank handle safely.
- When full weight of trailer is resting on tractor:
- Check for enough clearance between rear of tractor frame and landing gear. (When tractor turns sharply, it must not hit landing gear.)
- Check that there is enough clearance between the top of the tractor tires and the nose of the trailer.
Step 16: Remove Trailer Wheel Chocks
- Remove and store wheel chocks in a safe place.