Fresh Water Tank Leak

[8e3k0]

Have been monitoring the fresh water tank tank each time we filled tank to the the fill spout. Guess what; we have a leak somewhere that drips over a 24 to 48 hour period in the area of where the hitch is attached on the driver side. I suspect it is either where the fill hose connects to the tank or the tank leaks somewhere at the top area. This means the whole insulated area under the tank will be saturated with moisture. Also now the dealer will have to drop the rear stabilizers, the rear hitch plus other attached items inclusive of the insulated bottom to verify and reapair. Earlier in the year we did not fill the tank to the full level as we were only doing short trips so no leaks were evident. Why can't they install something like this correct with no callbacks??? This is getting very annoying and getting to the point where I just don't understand how they can keep putting out poor quality in workmanship. Over on another board I have read where water tanks are literally falling down from their RVs because of poor supports and a lack of fastners.
Has any one else had fresh water tank leaks and if so what was the problem?? Thanks and appreciate any feedback. Ellis

[greener]

On our old 5er if we filled the water tank up completely it would run out an overflow vent (which is probably the air vent for the tank.Since it wasn`t a covered bottom we could see it leaking immediately. I don`t know if this would apply to your situation or not. I can sympathize with your frustration. Hope it`s a simple fix.

[KTManiac]

I just filled mine full for the first time, and it was leaking down the outside of the drain hose. It wasn't a huge leak, just kind of dripping slowly. Up until now, I had just been filling the tank 1/3 - 2/3 full (using the power fill) for water while on the road, and hook up to city water when at our destination. I have faithfully been opening the gravity fill cap when using the power fill, as per the owners manual.

This last trip, we were going boondocking for a week, so I wanted a completely full tank because we would be miles and miles from anywhere that had water available.

This time, I even turned down the flow of water when the tank got to 2/3 full because I was concerned about too much pressure building in the tank. As soon as water started overflowing out of the gravity fill neck and vent, I shut off the power fill .....and, the drip, drip, dripping started. At first I thought that I had not tightened the drain hose cap enough, but that was not the case. It was leaking somewhere and dripping off of the outside of the hose. I hope it is just a loose hose clamp, leaking seal at a tank sensor, or something simple like that. I won't know for sure until the belly pan comes off for some other reason, because at this point, the leak is not bad enough to pull it off for just that.

We will be going to the Fall Rally soon, so maybe I will have to schedule an appointment with the Team Montana Service Center, or stop in New Castle, IN at Walnut Ridge RV for some warranty work while we are in the neighborhood before my warranty expires.

These new holding tanks are springing leaks left and right from what I have been reading lately. On my old '96 SOB TT, the tanks are bullet proof, spun polypropylene, at least 3/16" thick. I'm not sure, but the tanks on the Montana appear to be a lot thinner, and made out of ABS or something else that is more brittle than polypropylene.

Also, the way that they glue all of the fittings to them, instead of using bolted on flanges with gaskets, seems cheesy to me. It appears to me that most holding tank failures are cracks where the fittings are glued to them. I just cross my fingers that my black tank never springs a leak! If it ever does, I will not replace it with a tank that is the same, I will have one custom spun/built out of thick polypropylene with proper fittings.

[8e3k0]

When I get home tonight I will check to see if the drip, drip stopped or if it continues. Will also check to see if the indicator comes off the full level indication with this continual drip. Ellis

[Jolu]

8e3KO,
That drain tube from the fresh water tank is suspect also. If I remember correctly it is attached to the tank fitting with a hose clamp. It could leak from there and travel in the under belly skin.

Under the tank there is probably a layer of foil insulation on top of the belly skin. The tank sits between floor trusses with aluminum floor joist above those. The insulation is above the floor trusses with a fiber wrap over the insulation and above the floor joist.

If your 3400RL has the tank in the rear the rear stabilizers may need to removed and the belly skin dropped in that area to view the tank.