I just looked, there is no valve i cam find. But there MIGHT be a pin, At the corner there is a round bar thing for lack of a better word that sticks out around a 1/4th an inch. I dont see a pin on the outside but it may have one inside. I will figure out how to get my fat ### in the trailer with only a swing after i dump. And then i will see if it is there.
It does swing gate though. Last load was a swing and it worked fine.
edit: wow i cant english tonight.