wht01ranger
+1y
sounds like you blew something bro.
if the hiss starts immediately after you hit the lift switch, the valve may be bad or you have a blown air line. if it will hold air and then hiss out, you may have a blown bag with a small hole. enough to hold air for a small psi and then let out once you lift it more.
it's possible its the valve, but highly doubt it
may want to go ahead and check your driver front air stuff as well