Preparing the Trailer for Uncoupling
P4 DM Ch21; CasGen5 DM Ch20
Before using the air valve to unlock a fifth wheel kingpin, prepare the trailer as follows.
- Apply the tractor and trailer parking brakes.
- Chock the trailer rear wheels.
- Lower the trailer landing gear until the weight is removed from the fifth wheel.
- Disconnect the tractor-to-trailer air lines and electrical cable. Plug the air lines to prevent dirt or foreign material from entering the lines.
Note: