Losing water from the fresh water tank???

[Vet4jdc]

I loaded about 30 gallons of water in the fresh water tank and drove 6 hours on Friday from Va Beach to Blacksburg, Va. We used about 25 gallons or so over the course of two days tailgating at the Va. Tech football game. We left Blacksburg this morning and only had a couple of gallons in the tank. The water pump stopped picking it up so I knew it was close to empty.


Tonight when we got home I had a small amount of water dripping from the low point drain. Not sure where its coming from? I turned the valve and drained about 1 1/2 gallons from the tank. Any ideas where the water dripping is coming from?


EDIT: I ran about 10 gallons in the tank tonight and now it's bone dry at the low point drain??

[Carl n Susan]

A number of MHC owners have reported they lose water from the fresh water tank when traveling. Apparently the have a propensity to siphon it of the overflow point. I recall some have put a cork in there when traveling. A Search on HC water loss or such should expose those earlier discussions.


On Edit: Here is a link to one of many discussions of this very problem using the Search Terms "fresh water loss".

https://www.montanaowners.com/forums...ad.php?t=78836

[Ram Montana High Country]

I might be in the minority but prefer to travel with full water - of course I always arrive with 2/3. I had an interesting thought - it would be interesting if ALL the water ran thru the fresh water tank on shore pressure. might work if the over flow was blocked off. Two benefits, IMHO, 1st always have fresher water in tank & 2nd tank would stay full.

[rohrmann]

Not sure the fresh water tank system can handle city water pressure. It would take a total rebuild of the plumbing to make that work.

[Ram Montana High Country]

Good point - I always run a pressure regulator, set @ 55 but have seen it creep to 60 on occasion. Might be a new way to wash off the top of coroplast. Kidding

[Vet4jdc]

Update.

I checked the tank and low point drain today and everything is STILL dry. Not one drop of water loss today. I don't think I have a leak but I'm not sure why water would splash out the overflow vent and end up dripping out at the low point drain?

Anyone have any ideas?

I currently have about 10 gallons of water in it. My next step is to fill it full and sit for a few days and see if I have a leak then?

[jimcol]

Just a couple of thoughts. Could be the low point drain valve was not completely sealing. Either a piece of debris right on the valve or last time you used it didn't get it rotated completely to the closed position. Like you suggested fill her up and watch but you comments suggest the problem has already disappeared.

[daglenn1960]

2021 3121RL: We have had a leak around the fresh tank drain since the day we brought the rig home and filled water for the first time. On a recent trip to Colorado, under a heavy drought, we got a bit fed up with the inability to hold a full tank of water traveling to our next site. So, we dropped the coroplast and had a look:



Issue #1: (see pic at https://www.amazon.com/photos/shared...TM71BCrB_cLdtM) It appears the tank was dropped on the tank water overflow outlet which cracked it across both sides of the spin weld. When the tank got to a bit over 2/3 full it would expand and leak from this crack. Currently relying on some FlexSeal to prevent further leaking (temp fix, but working so far). Troubling, and the next step will be trying to get this warrantied.

Issue #2: the overflow hose didn't seem to be ideally routed it seemed to be exacerbating the crack/tank-expansion when filling as it took quite a bit of pressure to 'burp' the water as the tank filled. Re-routed a bit (less of a drop) and it fills much better with a more normal overflow/output.

Semi-solution #3: to hold a full tank when driving we have started to use a rubber cork/stopper placed in the overflow. No more siphoning and we arrive with all the water. Another item for the checklist, but it works.

[daglenn1960]

2021 3121RL: We have had a leak around the fresh tank drain since the day we brought the rig home and filled water for the first time. On a recent trip to Colorado, under a heavy drought, we got a bit fed up with the inability to hold a full tank of water traveling to our next site. So, we dropped the coroplast and had a look:



Issue #1: (see pic) It appears the tank was dropped on the tank water overflow outlet which cracked it across both sides of the spin weld. When the tank got to a bit over 2/3 full (note the 2/3 tank sensor bolt in the pic) it would expand and leak from this crack. Currently relying on some FlexSeal to prevent further leaking (temp fix, but working so far). Troubling, and the next step will be trying to get this warrantied.

Issue #2: the overflow hose didn't seem to be ideally routed it seemed to be exacerbating the crack/tank-expansion when filling as it took quite a bit of pressure to 'burp' the water as the tank filled. Re-routed a bit (less of a drop) and it fills much better with a more normal overflow/output.

Semi-solution #3: to hold a full tank when driving we have started to use a rubber cork/stopper placed in the overflow. No more siphoning and we arrive with all the water. Another item for the checklist, but it works.

[daglenn1960]

2021 3121RL: We have had a leak around the fresh tank drain since the day we brought the rig home and filled water for the first time. On a recent trip to Colorado, under a heavy drought, we got a bit fed up with the inability to hold a full tank of water traveling to our next site. So, we dropped the coroplast and had a look:



Issue #1: (see pic) It appears the tank was dropped on the tank water overflow outlet which cracked it across both sides of the spin weld. When the tank got to a bit over 2/3 full (note the 2/3 full tank sensor in the pic) it would expand and leak from this crack. Currently relying on some FlexSeal to prevent further leaking (temp fix, but working so far). Troubling, and the next step will be trying to get this warrantied. If that fails I'll plastic weld it.

Issue #2: the overflow hose didn't seem to be ideally routed it seemed to be exacerbating the crack/tank-expansion when filling as it took quite a bit of pressure to 'burp' the water as the tank filled. Re-routed a bit (less of a drop) and it fills much better with a more normal overflow/output.

Semi-solution #3: to hold a full tank when driving we have started to use a rubber cork/stopper placed in the overflow. No more siphoning and we arrive with all the water. Another item for the checklist, but it works.

[Blackduck]

When full, our 2017 Montana HC has lost up to 2/3 of the water out the fresh water vent located near the rear of the trailer while traveling as we ascend bridges, hills, and especially mountains. A regular size boat transom plug fits the vent hole and solves the problem. No tools are required to remove the plastic vent cover and bug screen, just remember to remove the boat plug and reinstall the bug screen and vent when you arrive at your destination.

[twindman]

You guys are lucky. My overflow vent is pretty well sealed up. I looked at it a few years ago and can see no way to open it.

[RipNC]

daglenn1960,

We have same rig and same water leakage issue. Have appointment in a couple weeks for warranty work. I wonder if ours is also cracked.

How much coroplast did you have to drop to get to this area?

Considering taking a look for myself before our appointment. Maybe we just have a loose hose issue at the overflow outlet on the tank. At least I'd know whether I'm getting BS'd or not.

[daglenn1960]

Had to remove about 6-8 nails on each side of the coroplast as well as the 4-way hitch/light plug (terribly mounted with a rear fiberglass cap) and the dozen or so screws across the rear that hold up the coroplast/rear. Not terrible (be sure to have a drill/driver and proper nut driver bit, plus a small nail puller). Pry the plastic washer thingie off the nail, spin the nails in reverse for a bit, get the pry tool under it and then spin it all the way out. Use self-tappers with fender washers (and maybe drill the nail hole a bit first) to replace. Had a nice paved, sloping site in Colorado to drop it in...

[RipNC]

Took a while for your post to populate (moderator helped). Thanks - very helpful photo too!