I have an XLR 24HFS which was (and still is) advertised as having a 57 gallon gray water capacity.. which is one of the key reasons I went with this trailer. After investigation, I found that it is an incorrect advertisement and the trailer only has a 31 gallon tank. Forest River sent me a 2nd gray water tank with the plan of having a dealer install it. After some back and forth between myself, Forest River, and the dealer, my only option for the installation is to do it myself (Dealer originally offered to do it but FR wouldn't pay. I fought with FR and got them to cover 3 hours, but now the dealer isn't confident about doing it...)
Mounting the tank will be easy. I'm just going to fabricate 2 cross members and drill & tap the frame so the cross members can easily be installed and removed if needed. As far as plumbing, my plan is to simply run the drain from the 2nd tank and tie it into the drain of the existing tank before the valve. But my concerns are whether or not the plumbing will actually work.
Concern 1) When filling the sealed tank (no drains will be going into the tank) from the bottom of the tank, the air that is inside the tank will have no where to go and will therefore prevent the tank from being able to fill.
Concern 2) If the tank can fill up, when it comes time to drain it, a vacuum will be created inside the tank and will hinder the draining of the tank.
Am I just over-thinking it, or are my concerns valid? As far as concern 2, this could easily be solved by installing a 1 way valve in the top of the tank that will allow air into the tank, but prevent the water from being able to leak out. I don't see any way to solve concern 1.
Sorry for the long post. Any help is appreciated!