Author Topic: Fresh water tank losing water  (Read 9930 times)

Paul Champagne

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Fresh water tank losing water
« on: December 17, 2014, 01:14:02 AM »
Hello my 2006 Thunder is losing water when I am travelling I filled it up before I left on a trip at the end of the day I lost 30plus gallons not sure how to stop the overflow from dumping the fresh water when travelling any suggestions?

Thanks

Paul
2006 Patriot Thunder
C13 525 hp

Gerald Farris

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Re: Fresh water tank losing water
« Reply #1 on: December 17, 2014, 01:26:59 AM »
Paul,
I am not positive how the overflow pipe is plumbed on your 06, but this was a common problem in the mid to late 90s on SMC designed Beavers. The solution for those coaches was to install a vacuum break at the high point in the overflow line. This prevents a syphoning effect from developing in the overflow line that depletes up to a third of the tank capacity. The same solution will probably work on your coach also.

Gerald   

Lee Welbanks

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Re: Fresh water tank losing water
« Reply #2 on: December 17, 2014, 04:30:46 AM »
Would they have plumbed them different for 06 Thunders, from what I've seen it is very possible. On my PT the overflow is right in the top of the tank, no dip tube just fitting in the top. Did they actually build any two of these the same???

Joel Ashley

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Re: Fresh water tank losing water
« Reply #3 on: December 17, 2014, 09:01:37 AM »
I doubt your overflow is involved, Paul, and I assume you've made sure there are no obvious leaks around the tank or a fixture somewhere that's left on or faulty - is your black or gray tank filling quicker than normal;  does it only happen when the pump is on on the highway, for example.

Check that your tank dump switch isn't faulty and road bumps aren't activating it enroute.  I'm not personally familiar with the associated wiring, but if there's a valve motor and a relay or solenoid involved, I've had such things go awry on the road.  With internal contacts that can carbon up, the carbon buildup closes the distance between contact points so that road bumps close them, activating the device they control.  It may be bouncing on and off on the highway, and just not been on after parking, so you haven't noticed water dumping then.

As I indicated, I'm not experienced with the fresh tank dump configuration, but I'd start by maneuvering the water bay fresh tank dump switch to see if it operates normally and isn't oversensitive, activating the valve too easily such as when affected by road bumps.  If it's OK, I'd then see if I could find the valve at the bottom outside of the tank;  an associated motor may have a solenoid or relay nearby that I could check for over-sensitivity or obvious tendency to short.

Others here may offer more familiarity with the fresh tank dump setup and offer suggestions.

Joel
« Last Edit: December 17, 2014, 09:11:25 AM by Joel Ashley »
Joel and Lee Rae Ashley
Clackamas, Oregon
36.9 ft. 2006 Monterey Ventura IV, aka"Monty Rae"
C9 400HP Cat

Gerald Farris

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Re: Fresh water tank losing water
« Reply #4 on: December 17, 2014, 02:07:09 PM »
Joel,
The fresh water dump valve may be leaking, but the likelihood of it opening and closing when going down the road is so remote because of the way that it operates that I would not consider that a possibility.

Gerald

Bill Sprague

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Re: Fresh water tank losing water
« Reply #5 on: December 17, 2014, 03:24:55 PM »
I doubt our valves are in the same place, but I too would suspect the valve.

On our 04 Monterey the valve and actuator were weakly connected.  Although the actuator tried to close the valve, it couldn't finish the job because it pushed itself out of the way.  I "reinforced" it with some stainless wire and it has worked for 9 years. 


David T. Richelderfer

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Re: Fresh water tank losing water
« Reply #6 on: December 17, 2014, 03:38:54 PM »
Of the 100 gallon fresh water tank capacity I rarely get to an end-of-day destination after filling in the morning with greater than about 70% of the water.  In my case the problem appears to be the overflow is located near the front of the tank.  If the coach is facing downward on a slope when I fill the tank - such as my driveway at home, then I am unable to fill the tank over 85% or so because the overflow will pour the water out.  I normally re-park on the street where it's level and I can top-off the tank to very near 100%.  With the overflow being located near the front of the tank I notice at every stop the coach leaves a long line of water right up to my coach's stopping point.  When I pull away from a stop the overflow never overflows.  If I brake going downhill, then I will lose water.  The overflow seems to flow under stopping and downhill conditions UNTIL the tank gets to about 70%.

And yes, the siphoning affect seems to be a problem, but as I read here on the Forum a few years ago, I turn off the filling flow and turn on the faucet at the water bay to stop the siphoning in 20-30 seconds.  Then I top-off the tank again slowly.
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Jerry Emert

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Re: Fresh water tank losing water
« Reply #7 on: December 17, 2014, 04:32:44 PM »
I had the same type of problem that wound up being my dump valve stuck open.  I tried to fill the tank and saw water come out but in my rookieness thought it was coming out the overflow.  Valve manually closed and I don't dare touch the dump switch any more.  Good luck and Merry Christmas to all!
Jerry, Chief USN Retired
2003 Patriot Thunder Lexington 40' 3 Slides
C-12 Ser#  2KS89983
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Steve Huber Co-Admin

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Re: Fresh water tank losing water
« Reply #8 on: December 17, 2014, 05:09:36 PM »
Dave,
I experience the same condition on my coach, fill to 100% (overflow) at home. Let sit for a day or so prior to leaving and after a few 100 miles on the road the tank reads 70%. Previous Contessa was same. No leaks (except time that toilet didn't completely shut off and filled black tank in about 100 miles!). Suspect "overflow" when moving/stopping.
In any case, 70 gallons is more than enough to get me to any place for a  refill.
Steve
Steve
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Joel Ashley

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Re: Fresh water tank losing water
« Reply #9 on: December 17, 2014, 08:36:02 PM »
Thanks for the input, Gerald - like most here I value your opinion.  Indeed it is unlikely the switch or other electrical component is Paul's culprit, but I thought it mentionable since I've had experience with relays and solenoids that close their point gaps with carbon over time and cause chaos.

I find it of interest that so many lose a third of their water on the road, because our Monterey has never displayed that symptom.  Having never explored the precise character of the overflow valve nor lost water through it, I assumed that it was built with one-way flow to resist contamination of the tank and that it was of a nature to resist slop out, but not internal pressure from city water fill.  If that is indeed the case, it seems reasonable to assume a lot of owners may have worn, blocked-open, or dirty overflow valves that are amenable to slop-out when they shouldn't be.

If the overflow "valve" is only an open conveyance, than apparently I've been relatively lucky not to ever lose water noticeably, and I presume it is nothing more than a pinched rubber tube that limits contamination from outside.

I still tend to suspect the dump valve in Paul's case, and obviously other members with personal experience agree.  It's just that I'd expect to see dripping water under the coach even while parked.

Joel

« Last Edit: December 17, 2014, 08:42:51 PM by Joel Ashley »
Joel and Lee Rae Ashley
Clackamas, Oregon
36.9 ft. 2006 Monterey Ventura IV, aka"Monty Rae"
C9 400HP Cat

Paul Champagne

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Re: Fresh water tank losing water
« Reply #10 on: December 18, 2014, 06:34:27 PM »
Hi There

Well it is not my dump valves as I just had those replaced with manual ones I believe their must be a vacuum switch somewhere near the overflow valve as my fresh water valve works fine. When going around a corner on the freeway you can see the trail of water running out of the tank so something is not shutting it off will have to take it in to Beaver in the spring to see what the problem is.

Thanks to everyone for their posts...Merry Christmas and safe travels

Paul
2006 Patriot Thunder
C13 525 hp

Gerald Farris

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Re: Fresh water tank losing water
« Reply #11 on: December 18, 2014, 08:07:57 PM »
Paul,
There is no overflow valve. The overflow or vent pipe is completely open at all times. Therefore, when water starts to run out for some reason, either from driving or overfilling, the water can create a siphoning effect that will draw water continuously until the vent line draws air from the tank to interrupt the siphoning effect. That is the reason that vacuum brakes were commonly installed at a high point in the vent (overflow) line on the SMC era coaches.

This is not as common a problem on Monaco coaches since the vent line is directly in the top of the tank, but with the coach on a slope or in a long turn, it can happen.

Gerald         
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