Fresh Water Tanks Falling Out

[CabinetmakerII]

While searching for the source of a foul order (dead mouse?) in our coach I discovered both fresh water tanks were falling out. The "rails" the tanks rest on are bent down in the center. The OSB (Orientated Strand Board(aka Chip Board) pad the tanks rest on between the rails is broken and pushing down on the belly pan. There was water on top of the belly pan witch had leaked from the crossover tube between tanks soaking the OSB. IMHO, the structure that supports the tanks are severely under-engineered. The 1 1/4" angle iron is not capable of carrying the weight of 50 gallons of water. I will attempt to post pictures but have not had much success with that on this forum... Nope, not smart enough to post a picture.

 

[Lynn1130]

Not saying that this caused your problem, but in my case rapidly filling the tanks to the point of over expansion caused exactly the same problem including the crossover leak and broken ply.

Repairs included a much thicker and better grade of ply and three overflow tubes that drain out under the tank. I can tell how full each tank is by which overflow is dripping as I fill, and I added a flow meter to my fill line to tell me how many gals of water have gone into the tank.

 

[CabinetmakerII]

Thanks for sharing... While disassembling the system to facilitate repairs we found kinked vent lines and failed structural members. I contend the tank supports are grossly inadequate, incapable of carrying the weight of a full tank of water (roughly 410 lbs) not to mention the superimposed loads created while traveling. I too utilize a flow meter when filling the tanks and do so quite slowly, stopping once or twice to allow the air to vent. I do not want to route the vent lines overboard as I feel I would loose to much water between home and camp.

 

[Lynn1130]

I put shut off valves on each of the vent lines. Once the tanks are full I close the valves to avoid water loss. I am still using the same straps that came with the unit and have had no issues since the change over to a stronger and thicker ply. As my service tech said "the tanks aren't going to fall out before we do the repairs" and I went off on the next camping trip prior to getting the repairs done. Personally, I don't think the straps are as much of a problem as the ply and once that gets wet it is going to fail.

If the vent lines were kinked then the tanks would expand while filling until you stopped to allow it to breath. Depending upon how much expansion took place, the ply would weaken and the crossover leak caused weaker ply. I am not sure what "structural members" might have failed and you could be correct in your case but the straps were/are not the issue with mine.