Daily Archives: June 27, 2016

How To Safely Couple And Uncouple Your Trailer – Part III

Professional truck drivers need to know a thing or two about coupling and uncoupling their tractors from their trailers. After all, hauling the load is what the job is all about.

So far, we’ve examined several aspects of the coupling process. from checking the trailer height to connecting up the air system. There’s more than a few things to consider when you are coupling up your trailer.

Today, we are going to pick up where we left off, just after the air system is checked. Now that you are ready, it is time to back under the trailer and get the show on the road.

Backing Under the Trailer

Now you are ready to back under the trailer and make the connection. Put the tractor into the lowest reverse gear and disengage the parking brake.

Remember, you must back under the trailer slowly. The trailer apron should make contact with your fifth wheel and lift the trailer onto the tractor. When you hear or feel the fifth wheel’s jaws close around the kingpin, stop.

Again, we cannot stress enough, go slowly. If you hit the kingpin too hard, you could cause major damage to anything or everything, from fifth wheel to landing gear or cargo.

Checking and Securing the Connection

Put your vehicle into low gear and gently pull forward, while the trailer brakes are still engaged. You want to make sure that the trailer is locked onto the tractor. When you feel resistance from the trailer, stop.

Once the connection has been made and is verified, put your vehicle in neutral and activate the trailer’s parking brakes. Shut off the engine and exit the vehicle to inspect your coupling.

Inspecting Your Coupling

Through this process, you should fully understand how to check to make sure your coupling is safe and secure. You will have to go under the trailer to inspect it. If necessary, bring a flashlight.

Ensure you check the following:

  • Ensure there isn’t excessive space between the apron and the fifth wheel. The trailer apron and the fifth wheel plate need to be in direct contact. If there is space, something is wrong.
    • If there is a problem, fix it before doing anything else. You may want to check to see if the ground is uneven or if the kingpin is on a ridge inside the jaws.
  • Go under the trailer and look at the throat of the fifth wheel. Make sure the fifth wheel jaws are closed and lock around the shank of the kingpin. If they are locked around the head, that is a problem.
  • Check the release arm. It should be in a locked position.
  • If there is a release arm, make sure the safety latch is in position over it.

Next up, it’s time to connect the electrical cord and check your air lines again.

Electrical and Air

If you haven’t already completed this step, plug the electrical cord into the trailer and fasten the safety latch. Make sure you don’t force a connection if it doesn’t fit.

Double check both your air lines and your electrical cord to make sure they are secure and undamaged. One of the better ways of doing this is to set your tractor brakes, release the trailer brakes and keep a keen ear out for any air leakage.

Also check to make sure the air lines and electrical cord are not snagged or that any moving parts aren’t resting on the catwalk.

Raising the Trailer Supports and Removing Chocks

Most trailer landing gear mechanisms have two speeds, low and high. Begin raising the landing gear in the lower speed. Once there is no more weight on the landing gear, switch to high speed.

Raise the landing gear all the way up. Never, ever drive with it only partially up, lest you get caught on railroads or other road obstructions. After the landing gear is raised, secure the crank handle.

Do a final check for enough clearance between the rear of the vehicle frame and the landing gear. If there is a tandem axle or sliding fifth wheel, this is even more important.

Once done, remove the wheel chocks and store them. This finishes Part III of our ongoing series on coupling and uncoupling. Now you’ve learned all the coupling basics. Join us next week when we take a look at what it takes to safely uncouple your trailer!