air ?????

what the hell? ok this just happened today.i tried lifting my back on my accord,i have a 94 4 door.with eai air cylinders and blue double vavles.(two valves on one block) and on one side it raised up like normal and the other side it raises with pressure and than goes back down,its like air is not staying in the cylinder.i dont think its the cylinder problem because this happened awhile ago and i just changed the front valve with the back and it worked perfect again.now its staring up again.all you hear is air going in and than coming back out.do you guys think my valve wont shut.just pushing air than letting it back out.?i really need help ...