Fresh water vent leak???

["007"]

Why is it necessary to fill tank to the over flow in the first place?
If your traveling from campground to campground 3/4 of a tank is more than enough to get you there.
We have gone four days with enough water for traveling below over flow.
If you are always boon docking you will need to get additional water from a lake or a traveling water tank truck I always found.
I hope you all can enjoy your travels with out creating a non problem in your travels.
Never had to check the extension of overflow tube into tank unless they have changed something with the top fitting for overflow and extended a pipe into tank, for what reason do not know, it should be a non issue, just do not fill tank to over flow condition to cause siphoning condition.
Here are some more answers to your question 10 pages of them.
For every gallon of water you may not need, your decreasing your carry weight by 8 lb's, if its a gas coach, you may need the additional weight for something else, if its a diesel not so much you have the money to waste and fuel.

[DrPhil]

Perhaps this really isn't an issue either, but I've always made it a point to travel with a full tank to avoid any sloshing around and associated possible handling issues. Also I like to keep a handle on my water usage so that I can more consistently bridge between sources I trust. Mostly this means filling at home with soften water only, and I gauge fresh water in and out to monitor.

[allynne]

Drifter Jake, I usually travel with a full fresh water tank and do as you suggest very low tech and simple. In addition to stop the siphon, it will stop leaking if the unit is slanted to the side with the overflow. Tat will start the siphon action again.

Al Sawyer
'05 Mt. Aire

[dp7]

Originally Posted by DrPhil

Yes, it works great. Intend to create a post on my plumbing mods - many of which I've shamelessly stollen from others herein, but here is a preview. My vent extension looks a bit convoluted, but partly I had to turn left because of the black tank position, and partly I choose multiple adaptors because I wasn't sure how high I was going to extend. I will also say that the overflow tube snakes up and around for convenience, but there is a ~1/16 inch hole just beyond the trim downward to the exit to break the siphon. This set up works GREAT!

This looks like a good way to prevent any seepage from the vent valve when water sloshes in the tank. Did you anchor the vent valve to the holding tanks? I wonder if the weight of the brass valve combined with the long moment arm & vibration with eventually cause cracking of the plastic fittings or tank hub?

[DrPhil]

No anchoring. Tight as a drum. The brass fitting is feather-weight and so are the plastic pipes. Light, robust, and it's rather protected in that space.