After shutting off the trailer air supply and locking the trailer brakes, what should you do next when uncoupling a trailer?

When uncoupling a trailer, the proper procedure includes backing up gently to relieve the pressure on the fifth wheel locking jaws. This action is crucial because it helps to ensure that the locking mechanism that secures the trailer to the truck is not under tension. By applying light reverse pressure, you can facilitate the release of the locking jaws, making it easier and safer to uncouple the trailer.

Successfully relieving this pressure aids in preventing damage to the coupling system and enhances safety by ensuring that the trailer can be safely detached without risk of mishaps such as unintentional movement. If the jaws are not properly released, it can be difficult or impossible to uncouple the trailer, leading to potential operational issues or safety hazards.

Other steps such as disconnecting the electrical supply are also necessary in the process but should be performed after ensuring that the coupling has been successfully and safely released. Ensuring the load is secure and driving forward to relieve pressure are not appropriate actions at this stage of uncoupling.