The Driver Basics: Uncoupling

Three Step Method

You’ve arrived at your destination and been instructed to drop (unhook) your trailer. Some shippers and receivers require that you drop the trailer while it is being loaded or unloaded. It may be that you’ve been instructed by dispatch or your company to drop and hook, this simple term means to uncouple from one trailer and couple to another.

Each driver performs this task according to their own training and habits. In the interest of safety and short term memory, I follow a simple three step method to uncouple.

STEP 1: DOLLY DOWN

First, lower the landing gear so that the trailer is firmly on the ground, and will not drop during steps 2 and 3. Lowering the legs of the landing gear is done by turning a hand powered crank, either clockwise or counter clockwise. Trailer manufacturing can’t seem to decide on which way they want the landing gear to operate. They also can’t seem to agree on the placement position for high and low speed in the in the crank’s gear box. There are two speeds, high and low. The gear box also has a neutral, which allows you to turn the handle with moving the legs. To change speed, you have to push or pull the hand crank into the desired position.

STEP 2: RELEASE JAW

There is a release handle built into the side of the fifth wheel. The handle is typically located on the driver’s side of the tractor. You simply pull the handle until it locks into the open position. Normally, the handle will have an insulated, red rubber cover on the handhold. But, over time they wear off and/or become coated with grease and oil. Some driver’s prefer to use a puller to lock the release handle into place. A puller is a long medal rod with a single or double hook on the end. The puller is used for better leverage when pulling the release handle, as well as, to allow the driver to avoid having to insert an arm between the trailer and the tractor wheels. Pulling the release handle can be both dangerous and messy. how to start trucking business

STEP 3: DISCONNECT

Finally, you want to disconnect the airlines and the electrical pigtail. Before going on make certain that the trailer brake valve inside the cab has been pulled out. The tractor valve is the red knob located on the dashboard or panel. Ideally, both the tractor’s (yellow knob) and the trailer brakes would have been set (engaged) prior to the driver beginning the uncoupling process.
(NOTE: This series of articles is intended as a training aid and refresher. It is written as such with understanding that the reader is aware of basic safety practices).
If you fail to engage the trailer brakes prior to disconnecting the grab hands, you will run the risk of being struck in the face, as compressed air is still being supplied to the brakes. Once you are certain it is safe to do so, disconnect the air lines and pigtail from the nose of the trailer and secure them to the storage bracket on the back of the tractor. This bracket is commonly referred to as a dummy hanger.

Finally, pull the tractor forward slowly until the trailer has cleared the fifth wheel and stop. You should be able to tell when the fifth wheel is clear because the rear frame of the tractor will raise up. The purpose of stopping is to insure that the trailer is stable and will not fall or sink into the ground or the pavement. It is always best to uncouple the trailer so that the legs of the trailer are on concrete, but this is not always an option. Once you have completed uncoupling from the trailer pull away and clear the trailer completely. The trailer itself is still subject to sink depending on several factors, which include the combined weight of the trailer and the freight inside, if any, the surface of the location the trailer is dropped and the length of time it is left there. It is your responsibility to insure that every reasonable effort is made to see that the trailer is safe and secure.

Additional, if you are staging a climate controlled trailer, always make certain that the reefer unit is working properly and the fuel tank is full, this will save the next driver any problem, you as a professional driver could have prevented.