# Problem with freshwater tank



## Brackenmisty (Mar 29, 2013)

The fresh water tank on our cheyenne 696g dumps half of it's load when on the move, when it is filled to 100%, it does not do It when it is filled to 50% anyone have any idea why this may be happening


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## Carl_n_Flo (May 10, 2005)

Yep!!!

It is flowing out of the overflow while you are driving along....

Happens all the time for us.

And by the way, don't believe what the panel tells you. It might say there is only 50% left in the tank, but it could be anything between 25% and 75%....it isn't very accurate. To that end, I doubt you will be losing 50% of your water....but you will lose some.

HTH
Carl


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## scept1c (May 10, 2005)

I'm not sure but I believe it is partially due to syphoning. 

I drilled a small hole in the overflow pipe high up towards the top near where it connects to the tank and it has helped. This should minimise the syphon effect.

It hasn't completely stopped. I think I asked Auto Trail about it and all they could say was that we shouldn't be travelling with a full tank. Not very practical when on the continent and staying on Aires etc.

Last week I went to a camp site in Portugal and hadn't filled up at the previous site. When I went to fill my tank I discovered that the water at the new site was a murky brown colour which I would not put in my tank, I only stayed there one night annoyed with myself for not following my rule to fill up with clean water whenever I find it.


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## readyforoff (Dec 28, 2013)

scept1c said:


> I'm not sure but I believe it is partially due to syphoning.
> 
> I drilled a small hole in the overflow pipe high up towards the top near where it connects to the tank and it has helped. This should minimise the syphon effect.
> 
> ...


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## andrewball1000 (Oct 16, 2009)

I had a similar problem on my Knaus. Initially I put a valve from a dive snorkel in the overflow. This allowed air in as the tank drained but not water out. 
Later I removed the whole overflow altogether and replaced it with an easier method of draining the tank. There is a thread on it here somewhere but I have no idea if it's relevant to ATs


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## jiwawa (Jun 22, 2007)

Andrewball1000, have you any idea why there are half a dozen posts prior to your last, with a date stamp of 01-01-1970?

Is this a recurrence of an old problem?


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