DIY replacement of grey water tank

[mazboy]

We have a 3402 and it has a crack somewhere on the top of the grey water tank. the size is something like 70X28.5 so it is the large tank.

does anyone know if the tank has any vents on top and does it just move on the two rails so you can easily push it to one rail to down the tank????

any suggestions.

[jcurtis934]

Don't have a 3402 and don't know how different it is from my 3800, but I can tell you that all tanks have a connection to a roof vent, that the tanks are tucked with one top lip under a fixed rail of some type and the other lip on top of a removable metal structure. Not really a big deal to drop bottom in order to drop tank. Chances are the tank has a split around the lip area.

[rohrmann]

On our 2012 3402RL I had a crack on the bottom of my grey tank this past year, and was able to repair it without dropping it. I also installed supports under it and the black tank before reinstalling the coroplast. You can see the top of the tank if you remove the plastic cover on the side of the convenience center. I think I remember there only being one connection to the tank on top, with the vent plumbed in above the connection. I had planned, if the leak was not accessible from below, to drop the tank, make repairs, and reinstall it instead of replacing it. I ordered a repair kit from www.plasti-mend.com

Our rig had two steel cross members, about 2 feet apart below the coroplast, neither one touching the tank. I added two additional braces, 1 1/2" angle iron, and installed foam blocking and one piece of 2X4 wood to the bottom of the tanks so when the braces were installed, would support the tanks every 12". Now, when the tanks are full, they do not sag, so I am confident that the tanks should be good to travel if they have fluid in them. Also, be prepared to have to tie up all the electric, hydraulic, and the tank flush pex when you drop the belly, and I also bought a box of the same TEK screws prior to doing this project and additional fender washers.