Fifth Wheels 3. Chock the front and rear of the trailer tires to pre- vent the trailer from moving. WARNING Do not use the trailer service brakes for parking; they are not designed for this purpose. If air bleeds out of the trailer air tank during parking, the vehicle could roll causing serious personal injury or prop- erty damage. 4. Lower the trailer landing gear until the weight is re- moved from the fifth wheel. 5. Disconnect the tractor-to-trailer air system lines and electrical cable. Plug the air lines to prevent dirt or foreign material from entering the lines. 6.
Release the kingpin locking mechanism by lifting the safety latch and pulling the lock control handle to the unlocked position. See Fig. 11.6 . 7. Slowly drive the tractor away from the trailer. 11.10