[Corey]

Just a few things I can guess at. The freash water tanks has an overflow elbow on top that should drain excess water out the bottom of the coach. Maybe the connection at the top of the tank is leaking? Or if you have the type of tank level guage that has sensors that penetrate the tank wall, it is possible the top one is leaking. Worse case might be a crack or split at the top of the tank. You should be able to see the tops of the tanks with a flashlight from the Aqua Hot side of the coach. You may have to revove some of the covers on the drivers side of the water bay to see what the real problem is.

[Bryan]

My coach was doing the exact same thing, but with the grey tank approaching full. So I just made sure I would stay under 90%. Well that worked for about 2,000 miles. Now I’m at Disney World and can’t seem to get the water bay dry. Stays damp around the base of the fresh water tank. Checked all the connections on the tops of the tanks and they seem dusty dry. Looks like I might be taking it somewhere and having the tank pulled after this trip.

[Archived]

I have that leak situation right now with my plastic fresh water tank around the halfway point. It must have a crack at about that point. It leaks much faster when full, and then slowly tapers off as the water leaks down. The pressure on the crack area will lessen as the amount of water above it (i.e. weight) decreases. I’m about to remove the cabinets around the tank to see what is going on.

[Bernie]

I think vigilance regarding tanks is a must. I had a stainless tank on my first coach develop minute leaks in the welded seams. We have heard about aluminum holding tanks being replaced, and now two coaches reporting water tank leaks, as yet in unknown places.

The problem is these types of leaks when they develop are very small, usually starting out so small they might evaporate before getting anything in the bay wet. But they don’t repair themselves and with the passage of time they grow. The leak is rarely a high volume leak, but often is big enough to keep the bay floor wet. When the leak has progressed to the point at which it is visible, either moisture that can be seen on the bay floor, or worse as a wet spot on the garage floor the chances are the bay floor has been damaged and needs replacement. I know because with the leak on my first bus that is what I had to repair in addition to rewelding the tank.

With the exception of corrosion causing a leak I think a lot of leaks are the result of the range of vibrations our coach exposes the tanks to. With the proper frequency, vibrations can destroy almost anything and that includes welded joints on our tanks. If your tanks are not visible, it helps to periodically inspect them for leaks. It is far less expensive to stop leaks before water damage occurs.

[Archived]

I’m actually chasing a small fresh water leak as well. Had the waste tank replaced as well as heater this year. Checking the fresh water outflow ports as well as fill pipes.
hopefully something easy and not a new tank.

[Archived]

FWIW small leaks are hard to find so I use paper towels in the suspected area of the leak. Even a drop or two of water will be noticeable. If the leak is on the top of the tank such as the fill point or lower on the side such as the overflow they will be easy to find, and may just involve a clamp tightening.

But when my water tank leaked it was at the seams and the water was never visible in the bay. In fact I never realized I had a leak until I saw water drip onto the garage floor.

When I have had my tank in and out on coaches I have learned to double clamp the rubber fitting at the outlet. That is where the paper towels come into play because leaks around the bottom likely cannot be seen but can be located by seeing where the towel gets wet.

[Alan]

Jon,

I have been using the paper towel technique for a couple weeks now trying to find the origin of the leak. The paper towel got me to the area below the drain/feed outlets.

We dried the bay out yesterday, will look again today to see if it’s leaked since last night. if it hasn’t, we will fill and see if it leaks then. If it does then we know it’s in the fill circuit. if not, then it’s back to the lower bungs. Maybe drain the tank and replace the hose that connects the tank to the copper pipe.

[Tad]

Great minds apparently think alike.

[Dean]

Emptied the fresh tank, pulled the drain and main water lines and checked. Replaced the drain hose and double banded the main water line. Filled and will check tomorrow morning to see if there is any water in the bay.

if it is still wet, then the only option is to pull the fresh tank and check all welds. Although, the tank is 15+ years old… Not sure a weld would just fail after that long. But I could be wrong 🙂

Good news from Jeff? If it’s a weld in the tank, it can be fixed. The fresh water tank being stainless shouldnt really have failed like an aluminum holding tank would fail.

[Archived]

Charles,

When my water tank welds failed it was because the stainless tank welds were ground and polished. They looked pretty, but over time and likely due to vibrations they developed porosity.

I pulled the tank, pressurized it to about 4 PSI and using soapy water blew bubbles, rewelded the area and thought I was done. After welding I pressurized it again, and more leaks showed up. After a couple of tries I just rewelded the entire tank. That cured it.

I noticed on the tanks on my 97 and 06 the welds are not ground and polished so I think the tank is going to last far longer, maybe forever. My guess on your tank is the leak may have been from the hose connection at the bottom.

If you do have a leak in the weld joint when you put as little as 4 PSI to that tank to isolate the leaks be prepared for some interesting and exciting noises which will clearly demonstrate why compressed air tanks are not rectangular.