Holding your water?

Alfred622 · 07-26-2005, 07:14 PM

We've got a new Sightseer that is just wonderful. Being new to Class A with onboard water, we filled our fresh water tank before leaving home (added water until it came out of the overflow tube). We then drove about 250 miles - mostly on Interstate. When we parked at our campsite, we were surprised to find our tank was only 1/2 full. There were no leaks anywhere. Another forum suggested water sloshing in the tank while driving ran out of the overflow tube. Could this account for 1/2 tank in 4 driving hours?

If so, any ideas as to how this can be prevented? A shutoff valve in the overflow tube??

Alfred622 · 07-26-2005, 07:14 PM

We've got a new Sightseer that is just wonderful. Being new to Class A with onboard water, we filled our fresh water tank before leaving home (added water until it came out of the overflow tube). We then drove about 250 miles - mostly on Interstate. When we parked at our campsite, we were surprised to find our tank was only 1/2 full. There were no leaks anywhere. Another forum suggested water sloshing in the tank while driving ran out of the overflow tube. Could this account for 1/2 tank in 4 driving hours?

If so, any ideas as to how this can be prevented? A shutoff valve in the overflow tube??

"007" · 07-26-2005, 08:33 PM

Alfred, Welcome to the forum

Your over flow pipe may enter your tank an extend down into the tank causing siphon action to pipe level. Over flow tube usually comes off top of tank. Why did you need a full tank were you dry camping?
If not you would save some gas money if you only place in a quarter of a tank, a full tank could be over 800lb of weight. Check with your dealer he may have an answer. Congrats on your new RV, many happy travels.

"007"

AKBrick · 07-27-2005, 01:45 AM

Hi Alfred,
In my '04 Brave, my water tank has a ball-valve to drain the tank. It is accessed from one of my storage compartments below the floor. I also have a lot of stuff in that compartment. I've often wondered what would happen if something shifted and hit that valve. Do you have one of those drain valve? If so, maybe it was knocked open slightly. I generally check to make sure everything is loaded below the valve and not beside or above it. I know I've bumped it a couple of times taking one of my chairs out.
Good luck,
AKBrick

minnie26a · 07-27-2005, 02:14 AM

Is your tank visible? I would try filling it again to see if it is really filling up. Maybe your overflow tube is connected wrong somehow. Otherwise, there must be a leak somewhere. Trace all water lines you can visibly see also, after filling. Keep your water pump on while doing this...if if runs every so often, there is a leak somewhere.

troth · 07-27-2005, 02:47 AM

All good advice here. And I have witnessed my own fresh water tank siphoning off to at least the 3/4 full level before I stopped it, so I'm sure 007's right-on about the internal dip tube. As a rule, when going boondocking, I never fill the fresh water tank completely full. I let it get about 7/8 full, maybe a tad more, just before any siphoning might occur.

J Stemler · 07-27-2005, 04:06 AM

Had the same thing happen to me first time we left for a dry camping trip to the Dover race track.. Filled the tank until water came out the overflow tube...during the ride...1/4 tank of water siphoned off...solved the problem by cutting the overflow tube and inserting a plastic shut off valve I purchased at the hardware store...now I fill the tank...close the valve and open it when I arrive....with a full tank of water

MrTransistor · 07-27-2005, 10:56 AM

Hi All,
Another Winnebago exclusive. We had the same problem with our 01 Adventurer, 03 Journey, and now with our 04 Horizon. The overflow is located at the front of the tank and every time you hit the brake a little water pours out the overflow. Solved the problem on the Adventurer with a ball valve in the overflow line. Couldn't get to the overflow on the Journey. The Horizon is accessible and I added pieces of plastic pipe and elbows to route the overflow to the rear of the tank then back to the front. This prevents water from draining when hitting the brakes or accelerating. Tank stays full no mater how long the trip. With this in mind, be creative, add a valve or reroute the lines if you can get to the overflow. If not, there's not much can be done short of a cloths pin or cap on the end of the drain pipe.

Outbumn · 07-27-2005, 04:13 PM

We have a 04 Sightseer. Our over flow comes off the side of the tank and have had this same problem. I put a valve in the overflow line right before it exits the service compartment. I fill the tank until it starts to overflow, then close the valve. This seams to work and we don't loose any water.

I have also heard there was a recall on the freshwater tank, but when I asked, our model was not on the list.

Cruisin · 07-28-2005, 06:42 AM

Alfred,

As has been mentioned, your water loss was due to siphoning, not sloshing out the vent, etc. The siphon is starting when you overfill the tank until water comes out the vent. Water will continue to siphon out the vent until the vent tube inside the tank starts sucking air which stops the siphoning. If the tube goes half way down into the tank, then you'll lose half of your water. Don't overfill the tank and you won't have the problem. You can alter the vent line, but remember it's there for a reason.

Alfred622 · 07-28-2005, 07:42 PM

Thanks, All, for your helpful advice! It is appreciated.

I know the ball valve on the tank drain is shut and does not leak. Either sloshing or siphoning is likely the problem. I'm glad it happens to others too. I'll see if I can determine how the overflow tube is connected to the tank. If it is a siphon potential, then partial filling might suffice. Otherwise a shutoff valve seems to be in order.

(Oh, we camp almost exclusively at State or National parks where running water at the campsite is very rare. We get electric sites about 50% of the time. Thus, we like full tank of water from home when we arrive!)

Clay L · 07-30-2005, 04:11 AM

The overflow/vent tube on mine (04 Sightseer 35N) does not extend down into the tank at all, so siphoning is not the issue. The tank is not very tall but covers a pretty large area so won't take much of a tip angle to slosh.
It's definitely sloshing that's the problem in mine I think.

I looked at the tank after I saw a similar post on another forum and it looks like I can add some tubing that extends up to the top of the compartment and then back down. I think that will fix the problem.

gunny · 07-30-2005, 06:27 AM

Alfred:
Before you install a shutoff valve, a couple of things to consider. If you go to fill the tank and forget to open the shut off valve, you might overpressure the tank, it might collapse the tank when you pump out the water. Make sure your sensors are giving a correct reading. On ours I sometimes read 1/3 and the next day be back at 2/3 or about anything else with no useage of water at all.

Thudman · 07-30-2005, 06:53 AM

Had same problem enroute to WIT GNR 2 weeks ago. Full tank went to 2/3 full during a 200 mile trip. Winnie is aware of problem & "fixed" mine at Forest City by adding a plastic tube to the vent line. Not so sure the mod worked, however. Lost more water from Winnie customer svc area to Rally grounds (about 1/2 mile?). No chance to siphon (I don't think, in such a short drive), so might be slosh factor. Have not driven w/full tank yet since the mod. Since your rig is new, warranty should take care of the fix.

Thudman

Duner · 07-31-2005, 05:41 PM

Alfred, Clay, & all,
I put a shower type shutoff valve on my vent line to keep water from sloshing out. These valves don't shut off 100% for safety in a shower. That fact is what allows air to enter back into the tank when you use water while camping, even with the valve closed. I learned that when I fill the tank thru the city water connection that I can open the gravity fill door to let it breathe while filling so I keep it closed all the time.

When we go to the desert sand dunes for 3-4 days dry camping you need all the water you can carry. It's nice to take a quick shower 2-3 times/day after a buggy run thru the dunes. My problem was I couldn't top off the tank without a spray all over my enclosed buggy trailer. I'd have to leave the water down about an inch from the top of the tank so it wouldn't splash out. I was short about 15-20% of the usable capacity. The shower valve works like a champ. I've added the valve on both my last two Winnie's

Happy Trails!
Bill

Adventurer · 08-01-2005, 09:19 AM

As you've probably noticed by now it's not an overflow, it's a vent. Filling it until it runs out the vent is overfilling and may cause the vent to siphon from the tank until something breaks the vacuum. No the vent doesn't extend into the tank. However it can still siphon out half a tank by collapsing the tank walls. The large flat top of the tank gets sucked down, and the sidewalls in. I noticed it once after overfilling my tank by accident that it kept running long after the hose was turned off. When I opened the storage compartment door, I was amazed how far the hard plastic tank had collapsed. I opened an inside faucet, broke the suction, and the tank made a load pop as the tank walls snapped back. Now I travel with an open bathroom faucet and have no more siphon problems.

The fix that some posted here, raising the end of the vent tube higher than the storage tank, works, unless you overfill and remove all the air from the tank, then it will still siphon until the vacuum is broken. Water tanks are like water heaters, they need some air space to work right, so use your gauge, not your vent, to tell when the tank is full.

Installing a valve in the vent line will work, as long as you always remember to open it when filling and when pumping. If you forget just once when filling, serious plumbing damage could occur. IMO Opening a faucet is much easier.

bchcmpr · 08-02-2005, 09:22 PM

have the same proplem the dealer added some hose to the overflowe to get the loop above the water level it helped somewhat but i am going to add a ballvalve since we do about 70%dry camping

Alfred622 · 08-06-2005, 07:49 PM

Additional Tip: Our motorhome is not exactly level when parked in the driveway - actually I have the front wheels on boards on the lawn. Nose is lower than the tail. So, guess what, the fresh water tank isn't level either. Since this Sightseer's vent comes from the top of the forward part of the tank, and the motorhome is "leaning forward", the vent starts draining before the tank is full! Actually, it looks like I am tilted enough to loose about 1/4 of a tank. So, while I thought I was leaving home with a full tank, actually it was only about 3/4 full. A little sloshing on the road and, wallah, arrive at the campsite with 1/2 tank. Well, I've put a removable plug on the vent. If this works for traveling, then I'll replace the plug with a valve inside the basement.

Gotta watch those levels!

DriVer · 08-06-2005, 08:24 PM

Went went some 17 miles from Southwick, MA to Springfield, MA with what I thought was a full tank however when we arived I only had about 3/4s or a tank of water. Bummer! I didn't know that this was happening to other folks as well.