Water syphoning while driving

Wildhorse · 05-17-2016, 09:18 PM

We're on our first real trip after about 5 or so weekends in our new trailer and have confirmed that water is syphoning from the vent while driving. On our weekend trips we would arrive showing 1/3 tank of fresh water after leaving home full. On this trip we are on I confirmed that it is indeed happening and not a gauge issue. Basically I filled the rank right before driving out of one campground enroute to the next about 45 minutes away. Other than a couple of right turns to get to and onto the highway the trip was pretty much straight. When we arrived the tank was showing 1/3 again. Here's where it gets interesting.

Being hellbent to see how much water was actually gone I put down the front jacks only and unhitched the truck so the nose of the trailer was slightly high, but not intentionally. It was just in this state to disconnect the truck. Before doing anything else I connected the fresh water hose and began filling the tank. While it was filling I dug out the electric cord and hooked it up, and then the cable. I got out two chairs and we just sat while the tank filled. It must have been twenty minutes to get it topped again so that water came out the side vent. At this point I turned the valve so that we were using the cities water and water was no longer flowing to fill our tank. I'm 100 percent certain of this!

At this point with a full tank and convinced that the water is syphining while we drive I went about leveling the trailer with the auto level system. When the front jacks dip down at the beginning of the cycle water began gushing from the side vent. When auto level was completed water was still running from the vent and continued to do so for 30 minutes give or take. When it stopped the gauge showed 1/3 full just like we have been seeing.

Anybody seen this before? Is there an obvious fix? FWIW, 2016 Raptor 355TS

gkainz · 05-18-2016, 05:58 AM

I don't think that's syphoning ... sounds to me like the vent line is mounted too low. But the only way to verify that is to physically look at the water tank.

slow · 05-18-2016, 10:30 AM

My thoughts:

It could be syphoning if any portion of your vent tube is higher than the outlet of the vent tube and if the vent tube was attached in error to a low point of the water tank and the vent tube outlet is low on the wall.

I would start by checking where the vent tube is attached to the water tank. It should be at a high point. Then make sure the vent tube slopes up from the water tank fitting to the outlet fitting on the wall.

**chuckster57** · 05-18-2016, 12:17 PM

Do you have two tanks joined together?

If so your equalizing tube between the tanks may be the issue. Seen it a few times. Sensors are on one tank, fills and shows full. Then the water finally "migrates" to the other tank and equalizes.

Wildhorse · 05-18-2016, 07:52 PM

I think I typed too much, so I'll shorten it up. When parked...

1. With the water tank topped off and not in the fill position, then...
2. Hit auto level and the front dips and water flows from the vent...
3. After the trailer is level water continues spilling onto ground until about 1/3 left...
4. The tank can be refilled and will not spill any out the vent.

I think this proofs out a syphon? Thoughts?

Wildhorse · 05-18-2016, 07:59 PM

Quote:

Originally Posted by chuckster57

Do you have two tanks joined together?

If so your equalizing tube between the tanks may be the issue. Seen it a few times. Sensors are on one tank, fills and shows full. Then the water finally "migrates" to the other tank and equalizes.

I don't know yet truthfully. We are on our way home and I'm going to look into this more next week. My wife is cleaning up a shattered shower door right now. I don't even remember hitting a bump today. I can see that we are not going to get bored with this thing. Before we left she secured everything and then I walked thru and looked for anything not ready to travel. The doors were secured. Go figure. I'm actually getting beyond frustrated. We're laughing at this piece of junk now.

FlyingChief · 05-19-2016, 07:41 AM

Wildhorse, we don't have two freshwater tanks - only 1.

gkainz · 05-19-2016, 08:41 AM

Quote:

Originally Posted by Wildhorse

I think I typed too much, so I'll shorten it up. When parked...

1. With the water tank topped off and not in the fill position, then...
2. Hit auto level and the front dips and water flows from the vent...
3. After the trailer is level water continues spilling onto ground until about 1/3 left...
4. The tank can be refilled and will not spill any out the vent.

I think this proofs out a syphon? Thoughts?

Point 4 supports your premise, I believe. However, I have no further ideas right now, except, if it were me, my next step would be to visually confirm the vent line ... straight, no sags or high spots, and confirm it connects to the fresh water tank on the top.

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