Fresh H20 tank losing water enroute

[rowekmr]

Hello
I have a 08 31 BHDS G2 and notice that after filling fresh water tanks and taking a short trip (3+ hours) that when I arrive the tanks have lost a lot of water. I originally thought my son didn't fill it up all the way the first time it happened so the next time I filled it up and I only had about 1/3 left and just last weekend after driving 3 1/2 hours I arrived with only 1/3 showing on gauge. I do notice sometimes in side mirrors when going over bumps that water comes out of the fresh water tank vents. Have anyone else noticed this and what did they do?

Thanks
Joe

[barrelslime]

I dont carry the extra weight of water in our tanks. I fill up at the CG. If its coming out in transit check all of your low drain point valves. If not that there may be a leak somewhere, but I dont know why it wont leak when parked. Are you taking the word of your tank sensors???? Or do you know for a fact it is leaking?? I never trust a tank sensor.

[McMonk]

We nearly-never travel with water in the tanks. Everything gets emptied (the extra weight = extra gas $$$$). When boondocking, I've been known to acquire clean drinking water in strange places (paid a homeowner $10.00 to fill my water tank once about 15km from where we were camping)

I have an 'overflow' on my tank... I suspect that as you're driving the water may be sloshing around and draining out of the overflow. Would that be possible??

[moonraker]

I was loosing a lot of water in route. We travel to racing events and want are water when we went . Three hoses vent under the unit with no screens on them. Didnt like the idea of bugs going in my fresh water . After a lot of thought I got three marine bilge pump white vents and mounted them in my outside shower box installed screens on them .Next I pulled the hoses up into
the water pump room . I had to make them longer Then i made a loop above the vent exit . this works great I fill the tank till it starts to come out the vent then open the drain to drop the level just a little bit :D

[Seann45]

Since I often camp where there is no water available I have to fill my tank before I leave as well. I had the same problem then I found that for some reason Jayco put an overflow right on the tank and it acts like a siphon. When it starts to work it will pull out over half the tank. so I plugged that overflow with a plastic bolt and just rely on the overflow at the fill spout now.

[Texas Sam]

I had the same siphoning problem with a 2009 G2 29RLS and my dealer fixed it under warranty. If I understood correctly, the technician added enough extra drain hose to each of the two drain hoses to make loops near the top of the fresh water tank. I envisioned them looking somewhat like a sink P-trap.

[RR Conductor]

I too had the same siphoning problem and had the problem fixed by my local RV repair facility while still under warranty. Seann is right though, you can rely on the overflow at the fill spout and simply plug the overflow at the tank if that's the culprit, but if your rig is still under warranty I'd get my dealer to make the repairs. The good news here is it "is" fixable but I assume by now you've long since had it done.