My rig is a 2019 (but recently bought new, never used) Jayco 27SGX fifth wheel. I left the campground today, after our first trip, with 1/3 level in my fresh water tank. I noticed water pouring out onto the road whenever I would turn to the left. I pulled into a large parking lot and had my wife watch while I made a left turn. She noted water coming out of what appears to be the fresh water tank vent located at the passenger side rear of the coach. There are two lines here, one is around 5/8" diameter water hose, and the other is around 1-1/4" corrugated plastic hose with a flattened rubber boot attached. The water is coming from the larger line with the boot. So...is this normal? Is there something that I should be doing to prevent this? It does not make sense to me to fill the fresh water tank, then have the water that you need spill out at each left turn. Thanks for any helpful replies.Ricky R

It's one of those thing called centrifugal force. A full coffee cup with no lid will spill if you apply the brakes. Same thing. Go get a tapered wine bottle cork, put a stainless screw in it with a short piece of string and insert it into the fill port. Problem solved, mine does the same thing.

I agree with Fisherman's resolution and cause, but ours has never done this. We have an overflow vent, in fact, we fill till we hear it "burp" and have never had it spill like described. Seems to me to be poor design, unless that's a Jayco thing, the vent that is.

We had a North Peak 5th wheel in which the vent line was routed so that we would lose three quarters of our freshwater on a trip to the campground. When we complain to North Peak they said that's the way they do all the vent lines. Not much help.We capped off 1 of the vent lines (On the driver side) and rerouted the other vent line to the vent located in the fill line. This solved the problem.

Thanks for all of the quick replies. I just thought that there may have been something I was missing, this is our 5th fifth wheel and we have never had any issues with any of the others. I agree with TenOC, poor design, I will look at DIY modifications.Thanks,Ricky R.

I had a similar thing happening, and it also happened when parked on a steep hill.I extended the overflow vent line about 15" above the top of the tank, and then down to vent out the bottom of the MH. I used a flexible CPAP hose. It stopped the problem.

Fresh Water Tank Overflowing When Turning | Good Sam Community

Fisherman
Explorer
Oct 23, 2020
It's one of those thing called centrifugal force. A full coffee cup with no lid will spill if you apply the brakes. Same thing. Go get a tapered wine bottle cork, put a stainless screw in it with a short piece of string and insert it into the fill port. Problem solved, mine does the same thing.
ReneeG
Explorer
Oct 23, 2020
I agree with Fisherman's resolution and cause, but ours has never done this. We have an overflow vent, in fact, we fill till we hear it "burp" and have never had it spill like described. Seems to me to be poor design, unless that's a Jayco thing, the vent that is.
TenOC
Nomad
Oct 23, 2020
We had a North Peak 5th wheel in which the vent line was routed so that we would lose three quarters of our freshwater on a trip to the campground. When we complain to North Peak they said that's the way they do all the vent lines. Not much help.

We capped off 1 of the vent lines (On the driver side) and rerouted the other vent line to the vent located in the fill line. This solved the problem.
Ricky_R
Explorer
Oct 23, 2020
Thanks for all of the quick replies. I just thought that there may have been something I was missing, this is our 5th fifth wheel and we have never had any issues with any of the others. I agree with TenOC, poor design, I will look at DIY modifications.

Thanks,
Ricky R.
Pangaea_Ron
Explorer
Oct 23, 2020
I had a similar thing happening, and it also happened when parked on a steep hill.

I extended the overflow vent line about 15" above the top of the tank, and then down to vent out the bottom of the MH. I used a flexible CPAP hose. It stopped the problem.
bukhrn
Explorer III
Oct 23, 2020
My class c does it, but not with only 1/3 tank, only when it's full.
Roger10378
Explorer II
Oct 23, 2020
The 1-1/4 in line would be the gravity fill on most of the older trailers. Do you have a gravity fill? If so my guess is that the tube has become disconnected.
Fisherman
Explorer
Oct 23, 2020
Roger10378 wrote:
The 1-1/4 in line would be the gravity fill on most of the older trailers. Do you have a gravity fill? If so my guess is that the tube has become disconnected.

I really doubt the line is disconnected otherwise the flood would be inside the trailer. More likely is that the fresh water holding tank is under the bed or similar place where the outside location of the fill point would prevent installing the fill point without having the hose visible through the wall inside. My fill point is about 2 inches above the tank, just under the sheet of plywood on the bed.
Lynnmor
Explorer
Oct 24, 2020
Roger10378 wrote:
The 1-1/4 in line would be the gravity fill on most of the older trailers. Do you have a gravity fill? If so my guess is that the tube has become disconnected.

That would my guess, I doubt that they used a 1-1/4" hose for a vent. Of course the RV industry will use anything and maybe they had some odd tanks to use up.
Pangaea_Ron
Explorer
Oct 24, 2020
I once talked with Winnebago about an issue on the road, without much success, but then I got a call back from a production team from their lunch table, and they offered suggestions. It was an amazing conversation. Ultimately, they asked me which day that my MH was completed. . . I said that I had no idea, and they said: It matters, they could have put that part anywhere depending on which day that it was completed.
Thanks, I think?