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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.