Need help finding the leaking black tank valve

[Ray Bates]

2021 Vista 31B. I purchased a new valve and went looking for a way to get to the old leaking valve. I know it is some where between the black tank and the water closet. The only thing I could find that looked like a removable panel in the area is behind the rear tires. Am I messing something or is that how you get to the valve?

[Morich]

Heah there! Looks like you've done a massive upgrade fro the old 04 model to the new RV! Congrats!

Looks like a good time to do some looking at the interactive parts catalog to find out what you now have?
https://catalog3d.winnebagoind.com/menu/Parts.htm

It let us "look through the walls" instead of having to crawl! Great stuff but it does take a bit to get the hang of the controls, so I might try to shed some light on where the valve might be found?

We can get drawings of WHERE but not HOW to get to it, so maybe only "some" help!

There are early and late builds but I see this part as being the same on both. The difference will be in your serial number having a 7th digit of 1 for early or 2 for later build, if you get into sorting other parts, there will likely be details which differ.

I did some snips of the drawing that shows that valve and looked for things you might be able to spot from underneath but did not get too much. I wonder if pressing up on the bottom cover will let you"feel" some of the pipes, etc that might help?

It looks like you have a long cable that goes in and then bends back to attach to the valve. That often means there can be a problem with the cables and clamps getting somewhat loose, so that pulling on the handle can move the valve less than it should. Maybe be aware of that and look for any loose attachment points?
Have you dealt with this type cable on lawn mowers, etc that the clamp location is a big factor in how much the cable moves?
When the clamps get loose the outer "cover/layer" can move instead of the wire inside that does the work! Same idea, I believe!
Click these for best view!
From top

From bottom???? I think they have given us wrong info on the length of this pipe! I suspect it should be in metric. not inches as I doubt the bath is ten feet across? Larger than most RV get if it is!! But maybe something to consider as most of their drawings are metric but I will let you think about that as metric is not my game! I'm guessing about 1/3 of the way in from the side??

From side. I drew in dots for where the cable may run to bend back to the valve. Not exact for sure but idea! If you can find one of those three elbows to measure they are all shown as the same size/type so that may give an idea of how far left /right to expect to find the valve??


If you can find the edge of the black tank, that 120?? measurement is likely to get you close if you figure what they meant. inches or metric?

Possibly wrong info?


I'm told some of the little camera mounted on cable to use with a smart phone can be a lifesaver when working blind like this.
A $10-12 tool I keep thinking I want but I have too many now!

Wish you the best and keep us advised??

[Ray Bates]

Thanks so much for your research of my problem. I too looked at Winnebago's drawings and do have a pretty good idea where the valve should be.( right where you have the dashed line where the cable should curve around ). I have looked for any access panels in the compartments, under the coach, and inside -- nothing! The only thing that looks like a panel is behind the rear wheels where the valve should be, maybe. I can't believe Winnebago would bury a valve and not provide access without removing tires. The valve works ok but has a slow leak. I usually leave a little water in the black tank after cleaning and it is annoying to have that spill when I take the cover off the outlet. I can either live with it or take it to a dealer, I have two dealers within an hours drive. I am an RV do-it-yourselfer so I hate to admit I can't fix it myself.

[Morich]

Kind of in the same boat. I hate to trust others as they so often have let me down! Kind of along the idea of what I might do?

I might consider if there would be any value in trying to really flush the space where the valve closes. I think of it as having a sliding "flap" that rides in a groove. I have seen things on newer Rv that get hung inthat groove so the flap doesn't go fully closed.
Things like plastic strapping gets left in tanks and finall can wind up in the valve.

As a last bold "prayer" I might try to fill the tank really full of just water and hope as all that water poured out it might float something out to clear the valve??
It doesn't seem like a newer RV should have a bad valve yet, so I keep thinking back to the bad attachments on the cable and something stuck in the valve.

Maybe just wishing, though! I've spent a fair amount of time wishing and hoping before finally biting the bullet to do the hard stuff!

What does the new RV have on the bottom side? My guess is that it is not close enough to any wheel well for acccess there as it looks too close to middle?? If it is the thin plastic type stuff, we used to be able to press up on the plastic as we moved around underneath and feel enough of the drains to sort how where we might find them.

Thin plastic or ridgid insulation board of some type?

[Ray Bates]

The bottom panels are solid and insulated. I went out today and ran the tank rinse for about 30 min and did some flushes. I worked the valve gate and out about 6 times. I let it drain. We have a trip planned in 10 days to a place without full hookups so I will test it and see if it is still leaking. This RV is less that 2 years old and had light use, low miles. I have been working on a short in the cameras, looks like a bad connector on the video switch box. The generator hour meter is stuck on 26 hours. I also had a leak of fluid from the rear axle that Ford repaired under warranty last week. I am just repairing one thing at a time - Overall the RV is built very well but does have some issues. If the black tank valve was installed without easy access that does point to a design flaw that should have been avoided. -- After I have clear information from a Winnebago tech I will post it here.

[Bones2003]

Hi Ray, I have a 2021 Vista 35U which has about the same layout with that black tank valve so I am very curious to hear how you finally access it. So please keep us posted! I haven't researched it very much but thought maybe by crawling into the basement compartment from the passenger side on mine. Of course I would need to weigh about 80lbs and have 5ft arms.

My generator hour meter quit at 37 hours. It just snaps into the panel so I bought one from Amazon for about $17. Looks like the exact same item.

Good luck!

[Ray Bates]

Bones2003, IF you look behind the rear wheels on the driver's side do you have a removable panel? I did look at the hour meters on Amazon but I ended up ordering from KIB. It cost the same as Amazon but the shipping cost more than the meter. I attached a valve on the sewer drain to catch the black tank leak until I figure out how to get to my black tank valve.

[Morich]

I've never dealt with the solid covering underneath so not much help on how to access, so maybe just some thinking on alternates that may not help much?
Sometimes just rattles some good info loose from folks who HAVE done it?

Can you see how it is attached? Screws, fit into lips, adheasives? If one takes a large section out by cutting an opening, how does one put it back?
Do we need to do it somewhat like sheetrock and add strips behind to attach it like we would on a studwall? Is this something that we might want to have a large sheet on hand to just double the layers when going back?

Interesting item which might prompt me to remove more and plan to go back with something like this as it seems to be less expensive and easier to work than I might have expected?
Underbelly material with lots of different trade names:
https://www.recpro.com/rv-underbelly-material/

Any of you guys out there that have done a remove/repair on the solid stuff underneath?

[Bones2003]

Ray, I won't have access to my RV for a couple of weeks. I will check it then and take photos if I find any access panels.

[Bones2003]

Originally Posted by Bones2003

Ray, I won't have access to my RV for a couple of weeks. I will check it then and take photos if I find any access panels.

Okay, I was finally able to look and there are no access panels by the rear wheels or under the RV in the area of the black tank valve. Perhaps if I remove the white panel in the picture below I could reach the valve. It would be a tight squeeze and a long reach from the looks of it.

[Ray Bates]

I took this picture of the back of the black tank valve by holding my iPhone and a flashlight in behind the water closet panel. the cable pulls on the back side straight towards the center of the camper. Replacing the valve and cable will not be easy but now I know where the valve is. I am not sure if I should replace it or rework the current plumbing to get a black tank valve into the water closet. Thanks to all who provided info! Ray

[Morich]

Whoopee! I get a view of what I've been guessing at from the drawings---I think!

Is the matching what your picture shows?


Assume no way getting that metal out is going to work?
So the hard headed part of me is still screaming that it will have to be worked from the bottom by taking part of that off?
So you say it is solid, does that mean like a solid foamboard of some type cloroplast or what do you have there?

No real info on the newer stuff but I'm thinking this is going to be somewhat like doing a repair in house plumbing that gets damaged in a wall. We have to cut out a section and then put something back to hide the damage we've done.
The bottom of an RV may not require near as much work to hide that damage as only us DIY guys are likely to see it!

I'm still leaning toward the easier and more sure way to get access is to cut the bottom!

I do see why the newer RV love the PEX as it sure looks simple and quick to throw it in !!! Home builders love it as no skill is needed to place that stuff!

[l1v3fr33ord1]

Judging by the picture, I expect the valve is two to three feet away from the wet bay "white panel." The drawings also imply it's on the driver-side of the coach centerline.

I'd carefully remove the wet bay white panel(s) and come at it from that direction. I did this with my former Class A, and after removing all that I could was able to climb into the compartment such that I could reach halfway across the coach.

My coach also had an access panel into the other half of the wet bay/piping from a inside passenger-side compartment. I was small enough to fit through the access panel. It was the only way to reach the in-tank fuel pump. I could reach the black tank outlet and the black tank dump valve.

As an example of what can be done, here are before and after photos of my first-pass work. On the second pass, I rebuilt the 3-inch pipe to place the grey and black water dump valves in front, directly above the clear section shown. No more cables.