Intermittent fresh water tank leaking/dripping

[Yoda]

Cate&Rob -- I'm likely to get these terms wrong, but is it the pressure or the flow rate of air that does the work to clear the lines (or some combination of both)?

This may sound crazy (what else is new?), but what I do is open the low point drains and, with my wet/dry vac set to blow (so there's a high volume of air with low pressure) open a faucet and blow air backwards through the plumbing system. Every time I've done this (when "winterizing") water has come out of the low point drains. I do each faucet (and the shower), alternating between hot and cold. Only lines I can't do are the toilet and washing machine.

Howard - I was going to say both. The pressure gets the water column in the pipe moving but the volume of flow over time keeps it in motion fast enough to exit the system. Cate&Rob I like your idea of using the shop vac. You can also use it to clear out the P-traps before adding antifreeze too.

Great discussion

Keith

[Jlawles2]

I use the pressure regulator setup just like a water hose, but since I have a valve on the air line, I just crack it slightly. I can then release the water easily throttling through the faucet valve, while the ball vale near the regulator slows the in rush of recharge air to build pressure in the system.

[Dgrothen]

Maybe I was luck by applying 15 lbs on the freshwater tank but I was also watching the tank for movement as I did have the coroplast removed as I was investigating. The freshwater tank did move but not that much. I was only looking for noticeable signs that it was holding air and it did hold the pressure for quite a while (~4 hrs). When I released the air pressure, I also did my best to release it as slow as I could. After doing the air pressure test on the freshwater tank I also did the same on the main water system with the same 15 lbs. Again, it also held the air pressure for another four hrs. I then turned around and added 25 gals or water to the freshwater tank and let it set over and had no visible leaks. And did the same with the main water systema nd also did not find any leaks. At this point, I have to chalk my water leak up to the one I found a month ago on the black tank flush where it would spray each time I used the black tank flush. I'm also using the fact that there was mold in the insulation as that the leak was a bit old. I think it takes at least 30 days for mold to start growing and there was plenty of it. I feel very confident that it fixed now and that the underbelly has been cleaned and free of mold now. What a job.

I've also replaced all the fiberglass with Styrofoam, except for where the freshwater take is, that is still fiberglass.