My green side air tank was leaking about 25 psi in an hour. That is well within spec., but enough to cause me to look for a leak. After soap testing every thing I could find, I was coming out from under the rig and noticed a solenoid valve tucked up behind the front bumper. Just for good measure I soap tested it also. Turned out that air was leaking from the discharge port of the valve. With some investigation, I determined that it was the air dump valve for the air bags. I was able to get a new valve from HWH and after installation, the leakage rate dropped to about 10 psi in 24 hours. This solenoid valve surprised me as it doesn't show up on the air sys. diagram or the HWH sys. diagram. On my rig, this valve is located just behind the front bumper with the discharge port facing forward. This is a very poor location and orientation for a valve such as this. That discharge port had collected a lot of dirt from road wash, etc., not to mention a mud wasp nest. Some of that stuff had gotten under the seat of the valve and caused the leakage condition. When I re-installed the new valve, I added a short piece of hose to the discharge port and taped a piece of filter material over the end. I don't know how many of this kind of valve and this poor location and orientation that HWH has in their systems, but I would recommend that owners be aware of this situation and look for a potential problem. Have a great day ---- Fritz