Trailer Spring Brake Valve or ????

How are you guys doing im running into an issue with my truck. When i set my trailer breaks the valve right under the cab that the air lines attach to it starts leaking air. I assumend something was wrong with the valve and i replaced it , it continued to do the same thing. When i took out the trailer line off i noticed that air was coming out of the emergency gland on the trailer when the brakes are set and that definitely isnt normal alongside that the button to make the pins go in/out in order to slide tandems isnt working as well like there is no pressure back there. When i press the valve inside cab in to air up the whole system it takes at least 20 seconds before i can drive it kind of feels like brakes dont release quickly. Im thinking is the trailer spring brake valve but need some opinions

 

When I set trailer brakes and disconnect the air line from truck to trailer air comes out of the trailer emergency Red gland where the airline goes until it drains the tanks in back pretty much

 

Any other input like I mentioned when the knobs are out that I disconnect the air line air comes out trailer red emergy gland which it shouldn't do that is it that air brake spring valve??