Problems with Slides not leveling

[powerscol]

What a quandary. I hate to think this, but if the water tank bulged enough to buckle the slide floor and distend the belly you probably have damaged the supporting tank structure. You should not see any bulge in the belly where the tank is. I would pull the belly plastic and at least take a look. The strapping or frame the tank sits on could be bent. If it did damage the structure it could drop out during travel. Somewhere you have a blue vent line and as others have mentioned due to water loss while traveling they may have put a valve on it.

Good luck

Also take a few pictures of the underside and post here.

[Best Papa]

I am beginning to believe that there was another valve or cut off of some kind installed as an aftermarket for perhaps one of the reasons mentioned above. The previous owner did show me that he had added a second blackwater valve as the original tended to leak so perhaps he added something else for the freshwater. As we were looking for what may be causing the swelling of the floor we heard a pop that sounded like something hitting the unit but never saw anything so looking back I'm sure the pressure had broken or snapped a line or valve somewhere but there was no water coming out anywhere and the floor continued to rise from pressure from the water tank (we discovered later). I'm not sure what had happened in the plumbing system now and not sure how to even go about pulling it apart to look for the issue.

I know that the pressure relief was not working or else the system wouldn't have expanded like it did. I have never run across anything like this before or even heard of such a thing so it must have been something that was shut off or plugged.

[Canyonlight]

When you have feedback to share on my questions in my post #10 we can decide what to consider next.

By the way, this is the first I have heard in my several years on the forum of a fresh water tanking expanding and the impact you are referencing. I would be talking to the original owner(s) if you can to learn history of issues and mods. they/others may have done.

Pictures as some of us have asked for would be helpful......water panel, fresh tank drain/overflow tube area, "double pressure valve" you stated, etc.

Dan

[Best Papa]

You said you "pulled the drain"......is that referencing the white handle fresh water tank dump 2" tube behind the rear street side axle ? If so, the fresh water tank vent tube (blue pex tube extending just below the corroplast a few inches or so) as others have mentioned is located just inches from that. Is that what you see or have or is it differenet and if so in what way ?

Here is a threawhat the fresh water tank drain and vent tube looks like. This link also shows a picture of a 303 fresh water tank mount location over the rear axle with the blue vent tube extending a few inches above the tank.

https://www.mygrandrv.com/forum/show...=overflow+blue

Also, what is the "double pressure valve" you mention in your post #8 ?

It sounds like your fresh tank is not venting due to prior owner modification somewhere or the Kantleak panel may have a valve malfunction. We can cover this later if necessary.

Dan

I found a PVC cap on the blue relief valve that at first observation may be the cause but it pulled off easily by twisting it so I would think that with the kind of pressure I was experiencing would have blown it off. Question. If I hook up only the city water should the FW holding tank take on any water? If not and it is then does anybody know what valve or fitting might have failed?

[Canyonlight]

I found a PVC cap on the blue relief valve that at first observation may be the cause but it pulled off easily by twisting it so I would think that with the kind of pressure I was experiencing would have blown it off. Question. If I hook up only the city water should the FW holding tank take on any water? If not and it is then does anybody know what valve or fitting might have failed?

There have been reports over the early years with the Kantleak water panels where water was going into the tank when settings were on city pressurized water. Most likely the cartridge needs to be replaced.

It was learned over the years that rotating the cartridge valve among the four settings under pressure resulted in the O rings moving out of position on the cartridge. Not being lubricated well enough using the plumbers grease is also an issue noticed when the cartridge valve turns quite hard. It should rotate easily when lubed properly and not under pressure.

In addition, it seemed there was advice from Anderson Brass to rotate the setting in the same direction (either always clockwise or counter clockwise) to further prevent O ring failure. This seems a little hard to control.

Here is area couple threads with some history on this. There are others as well. You can search Kantleak and/or cartridge and learn more about this in the appropriate threads.

https://www.mygrandrv.com/forum/show...ight=cartridge

https://www.mygrandrv.com/forum/show...ight=cartridge

Here is the link to Anderson Brass to contact them to get a new cartridge. Many of us have replaced these. New cartridges come with instructions on how to replace.....pretty easy to do. https://www.abcorv.com/

Here is a picture of the new cartridge I received and installed in 2015:


Dan

[powerscol]

I found a PVC cap on the blue relief valve that at first observation may be the cause but it pulled off easily by twisting it so I would think that with the kind of pressure I was experiencing would have blown it off. Question. If I hook up only the city water should the FW holding tank take on any water? If not and it is then does anybody know what valve or fitting might have failed?

You say you removed a cap from the blue relief valve? Are you saying you found a valve on the blue vent line and the valve had a cap on it? Is the valve open? If it is a ball valve the handle will be inline with the pipe while open. My guess the previous owner had the cap on it to keep critters and dirt out of the valve.

As to pressure blowing it off, it did not see that much pressure. It does not take much to bust the tank out, maybe 2-3 PSI. You really need to drop the belly, or have a technician check for you to see what damage was done to the tank support structure. Its fairly easy to do, just undo the screws along the edge and drop the plastic down. I would not travel until you have this checked out.

Also pictures would really help.

[Best Papa]

Dan, thanks for the above information. This weekend I'll try pulling some things apart to see what I can see so the story goes. To powerscol: I found the blue overflow tube with a PVC cap stuck on it. If it's an overflow valve why did he have a PVC cap on it. Although this is first 5th wheel I've been RVing for years with trailers and tent trailers and have never experienced anything like this and hope that I haven't done any major damage.
I will post more this weekend when I get a chance to do more research.

[powerscol]

He probably had the cap on it to reduce water loss while traveling and to keep bugs from crawling up the tube into the tank.

[Bill G]

What really confuses me is that there should be some sort of shut of valve or something when the water tank is full so that this doesn't happen. When I turn back on the city water will it continue to bow now?

our 303 has an overflow tube on tank. maybe yours is plugged?