Fresh water tank

Bullitt92223 · 10-09-2016, 06:26 PM

Ok I have a 66 gal. fresh water tank in my 2012 Coachmen Mirada 32ds. My question is why when I fill up the tank tell it starts to come out the over flow line. I stop filling it up it continues to drain the tank until it is 2/3 full. This is a new to me rig I took it back to the dealer that I purchased from under the 60 day warranty. Had them look at it and was told that it is fine and that is how the it was built and there was nothing they can do about it. So now I am on my own and it just bugs the heck out of me. It is time for us to start our dry camping season with the dirt toys. I would like to be able to hold all the water that the rig was built for.

Thanks for the help
Jon

Davidceder · 10-09-2016, 07:02 PM

Fill it until it stops overflowing than keep emptying it into a 5 gallon bucket to see how much you really hold. At least start there....

SeaDog · 10-09-2016, 07:07 PM

It may be that that once you fill it up and it stops overflowing (back to 2/3) you will need to fill that last third slowly. It might be that the tank is not allowing all the air to escape durning normal filling. JMHO

**Bama Rambler** · 10-09-2016, 07:09 PM

First, are you actually looking at the level in the tank, or are you going by the indicator?
The indicator can be very misleading about the level.

If you're going by the physical level in the tank, it could be that the overflow is siphoning the water out until it breaks suction. You may be able to rework the overflow so that it doesn't siphon the water out. You could also put a valve on the overflow and shut it off as soon as the tank is full. However, be VERY careful using that valve because you can rupture the tank if you leave the valve closed and then fill the tank.

You can also starve the pump of water if you don't open it and you run the pump for a while.

Bullitt92223 · 10-09-2016, 07:50 PM

Quote:

Originally Posted by Davidceder

Fill it until it stops overflowing than keep emptying it into a 5 gallon bucket to see how much you really hold. At least start there....

The wife and I were talking about doing that to see what we have.

Bullitt92223 · 10-09-2016, 07:54 PM

Quote:

Originally Posted by Bama Rambler

First, are you actually looking at the level in the tank, or are you going by the indicator?
The indicator can be very misleading about the level.
.

Yes to both. I removed the cover so I can see the tank. It looks like I have two vent lines one on both sides of the tank. I have seen the water come out of ether line not at the same time.

**Bama Rambler** · 10-09-2016, 08:03 PM

Maybe one is a vent and one is an overflow.

Do they both route the same way (up or down)?

Bullitt92223 · 10-09-2016, 09:05 PM

Quote:

Originally Posted by Bama Rambler

Maybe one is a vent and one is an overflow.

Do they both route the same way (up or down)?

Both lines come from top of tank one driver side and one pass side. They do a 90 from the top over about 6" then 90 and down and out under the rig.

I have been doing some more research on the forum. It looks like some people have said that the vent/overflow hose is too far in the tank and causing it to siphon the water out. Now this has been on different rigs maybe that could be the problem. I would have to find out what it takes to remove the hose and then reinstall new clips on the lines.

**Bama Rambler** · 10-10-2016, 06:33 AM

The overflow should ideally be flush with the top of the tank and not protrude into the tank, but that's not the case in most installations. You may be able to pull the lines up a little and reseal them.

mfMcFroggierPod · 10-10-2016, 07:44 PM

I had a gravity fill the was lower than the top of the tank. I re-piped my fresh water fill to work with the city fill.

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Bullitt92223 · 10-10-2016, 08:10 PM

I had a min today to take some pics. The red line is the fill line right above it is one of the vent/overflow lines that is on the pass side. The line on driver side is like in the same spot just other side of the tank that is the last pic sorry I can't get it to rotate. As you can see in the pic the level of the water in the tank it was full. After it stopped draining out of the vent/overflow line that is what I have left in the tank.

mfMcFroggierPod · 10-10-2016, 09:06 PM

Are there two fresh water tanks?
Do you have two fill sources or a selector valve?
Is there a cross-over valve?
If one tank fill to top but the cross-over is slow to transfer this couldbe causing the level problem.

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**Bama Rambler** · 10-11-2016, 12:40 PM

It's hard to tell how far the overflows stick into the tank.

You show two overflows. Does it seem to be the same one each time that siphons the water out?

Bullitt92223 · 10-16-2016, 05:24 PM

Quote:

Originally Posted by mfMcFroggierPod

Are there two fresh water tanks?
Do you have two fill sources or a selector valve?
Is there a cross-over valve?
If one tank fill to top but the cross-over is slow to transfer this couldbe causing the level problem.

Sent from my iPhone using Forest River Forums

I only have one tank and one place to fill. The fill is a hose fitting right where I can hook up for city and flush black tank.

Bullitt92223 · 10-16-2016, 05:31 PM

Quote:

Originally Posted by Bama Rambler

It's hard to tell how far the overflows stick into the tank.

You show two overflows. Does it seem to be the same one each time that siphons the water out?

It depends on what way the rv is leaning when I fill the tank. So I have seen it come out of both lines but at different times. I am going to try and pull the tank out when I find replacement clamps they put on the lines.

Bullitt92223 · 10-16-2016, 05:35 PM

I wish to thank everyone that has replyed to this post. I will post updates when I get time to work on it.

NMWildcat · 10-16-2016, 05:45 PM

My rig does the exact same thing as far as siphoning out the overflow tube once full. Water fill is gravity fed. I fill it until it starts coming out the overflow, then put a cap on the end of the overflow tube (I installed a threaded barb fitting). Once we take a shower or two I take the cap off, but it's not really necessary as the vent tube relieves any suction. We mainly boondock and this solution has worked for 5 years.

mfMcFroggierPod · 10-16-2016, 08:32 PM

What is picture 3:5?
It looks like 2 tanks but you say it is one.
Do you fresh water tanks fill via a gravity fill or a pressure fill?

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Skyliner · 10-16-2016, 10:14 PM

My overflow is about an inch below the top of the tank on my camper and in front of the tank. I park my camper uphill and this allows me to get almost a 100% fill. I also have a cap on the overflow line so that bumps in road do not cause me to lose water.

mfMcFroggierPod · 10-16-2016, 10:18 PM

Where does your fill line enter the tank in relation to tank top?

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