Safety Tips

Coupling and Uncoupling a Tractor-Trailer

Scot Barney
5 minutes

Guide to Couple and Uncouple a Tractor Trailer

Here is a refresher on coupling and uncoupling a tractor-trailer. I understand that, with as many drop and hooks as we do in this industry, it may seem a bit redundant. I received a wake-up call while loading a CO2 trailer, something that I had done so many times that was sure that I could do it in my sleep. It was a reminder to stay in the moment, focus on the task at hand, and beware of complacency.

It's a common procedure, but it's important to go back to the basics occasionally.

Here's a condensed guide to knock the cobwebs loose, and for a more detailed demonstration, check out this video from LGT’s YouTube channel.

Coupling a Tractor-Trailer:

1. Preparation:
  • Ensure the fifth wheel is in good condition and in the open position.
  • Check that wheels are chocked.
  • If you’re in a cold climate, make sure the jaws of the fifth wheel aren’t iced up.
2. Trailer Setup:
  • Start the truck and ensure the parking valves are out.
  • Build brake air pressure to at least 90psi.
  • Open the driver-side window for better visibility and hearing.
3. Positioning:
  • Back up so the kingpin aligns with the fifth wheel.
  • Check the height and alignment of the fifth wheel and kingpin. Danged new-fangled trailers with no front fenders.
  • Take your time, this probably isn’t a truck rodeo. Get out and get your eyes on it. Make sure that the fifth wheel will lift the trailer a bit. Don’t want to high-hook it.
4. Locking and Testing:
  • Lock the fifth wheel.
  • Perform a tug test to confirm secure locking.
  • Hook up airlines and inspect the kingpin with a flashlight. Ensure that the fifth wheel jaws latched onto the kingpin and that the kingpin isn’t sitting on top of the jaws.
5. Final Steps:
  • Raise the landing gear and stow the handle.
  • Remove wheel chocks and do a walk-around inspection.

Uncoupling a Tractor-Trailer:

1. Setup:
  • Park on solid level ground. If the ground isn’t stable, place pads under your landing gear. Some of our carriers do not want loaded trailers dropped on anything but concrete. You absolutely do not want a trailer that you dropped to sink into the ground. Emails will fly.
  • Keep the unit aligned for coupling and uncoupling.
2. Initial Steps:
  • Engage the trailer parking brake, then back against the trailer.
  • Pull out the tractor parking brake, dump your trailer airbags, and chock the wheels. Pull out the tractor parking brake, dump your trailer airbags, and chock the wheels.
3. Landing Gear and Disconnection:
  • Lower the landing gear until it touches the ground.
  • Lock the airlock system or install the gladhand lock.
  • Disconnect air and electric lines, then do your walk around inspection.
4. Final Uncoupling:
  • Pull the fifth wheel pin, slowly pull forward, and Bob’s your uncle.

Hope you all had a great holiday season and have a prosperous year ahead. Thank you for all your hard work and dedication.

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