[Richard and Rhonda]

Over the winter I noticed that I heard hissing from one of the rear ride height valves. I knew I had an air leak. If you study the air diagram provided by Steve Bare in another thread, it will be apparent that a leak in the HCV will quickly cause you to loose supply air because the HCV is supplied directly by supply air. The leveling solenoids are AFTER or BETWEEN the HCV and the air bags. That's why your supply air can go to zero but the bags stay inflated.

The valves were made by Ridewell, but the model is no longer available and has been replaced by a new model also made by Ridewell.

Here are the things I learned during the replacement process. They may help you with this little project some day. You can read about the valve at this link. http://www.ridewellcorp.com/Web/Site.nsf/Files/HCVLit0409.pdf/$file/HCVLit0409.pdf?bcsi_scan_6E1440D72CECFFE5=384QHIGC Kyk1DUxz9jY0elzwxj9RAAAARBJbCg==&bcsi_scan_filenam e=HCVLit0409.pdf
It is available from many sources on line.

First the existing valves use through bolts to fasten the valve to the frame. There are nuts on the back of those bolts, so you do have to access the nuts to get the original valve loose. You will find this a challenge unless your arms are nine feet long. I jacked up the coach and blocked it of course. I ended up sitting up behind the rear duallies so that I could snake my wrench to the nuts. Remember how you do this, because you will have to do it to reattach the new valve. The new valves don't use through bolts. They use studs that slide into the back of the valve. No fear, the studs line up with the old holes.

Second thing is the air supply line is the one on TOP of the existing valve. Mark it, or you will have to pressurize the system to identify which one is the supply line.

Third thing is the new valves have 3/8 push in fittings. My coach had 1/4 tubing going to the HCV, so I had to fab an adaptor. I used male female DOT fittings I sourced from McMaster Carr to do this.

Fourth thing. Get all the air lines attached BEFORE you bolt the valve to the chassis. It's a lot easier that way. Trust me.

Fifth thing, study the black dial on the new valve carefully. You can spin it 360 degrees. Alignment in one direction causes raise and lower with up and down movement of the rod. It is opposite for the other side (right vs left) Look carefully at this feature and figure it out before attaching the action arm to the valve. Easiest thing to remember is that if the arm is pointing down, you want the black disc to be exhausting air. If you find you are backwards from this on the side you are working on, rotate the black dial 180 degrees.

5.5 thing, the front HCV needs a tee to split into both sides. The old valve has two ports, the new one only one, so plan both for the tee and conversion from 3/8 to 1/4 tubing.

Sixth thing, replace one, replace them all. I knew one was cracked, another had a crack that just started.

Seventh thing, utitlize a helper, preferably one with nine foot long arms that doesn't mind crawling under the coach multiple times.

Eighth thing. GOOP is wonderful at removing grease from your hands, and face, and hair ( oh wait I don't have hair, so your head)

Have fun.