[encantotom]

a few thoughts.

1st....it would help to know what it is supplying air to.

my experience is with the solenoids/manifolds that are NOT for the leveling system, that it is two things that cause the exhaust port to leak.

1. i can be a piece of gunk got stuck in one of the valves keeping it open. occassionally you can do what larry said and clean up what you can, but i have not had good luck with that. i had a leaky solenoid on the bode air door and replaced it. it still leaked. ended up i had gotten a bad solenoid and a second one fixed it. but that took me a while to troubleshoot.

2. what i have had happen several times is that when the exhaust port is hissing, then if the manifold was supplying air to any kind of a piston/ram (like our air doors and open and close cylinders for the sewer dump or the ram for an air powered generator slide or a air ram for the genny) is that the seal inside the piston/cylinder is bad. that causes the air that is on one side of the ram to leak by and come back out the exhaust port. i have had to rebuild the 2 sewer ones as well as the ram for my air slide on my basement freezer/fridge.

tom