Black water valve stuck...

[Marcoiv]

My son and I removed the underbelly panel and located a leak right on the black water valve which I assume indicates an old seal. Certainly glad it is not a crack in the tank... However...

After taking out the bolts the valve seems free but will NOT slide out. We can't seem to separate the tank from the pipe enough to let the valve slip out. We removed the bolts on the gray water valve as well, hoping if we took that out we'd be able to move the pipe enough to pull the black water valve. No luck.

Weirdest thing... they seem free, but will just not slip out.

Anyone have this problem, or know what we're missing here... ?
Thanks!

[Carl n Susan]

As I recall, there is a lip on each side of the valve which fits into the hub of the pipe connections. It is not too big but I recall it hangs up unless you can get the drain pipe to clear.

You don't say what year and model Montana you have, but usually you can cut the sewer pipe downstream from the Y connection (which ties in the black and grey tank drain lines). Cut out about an inch of pipe and then you can get clearance to remove the valve easily. It also helps when reinstalling and to not let the seals move causing more problems. Use a 3" no-hub flexible connector to cover the cut area. Doing this also gives a little flex to the drain lines and may prevent future cracking of the spud on the tanks and causing a more difficult to repair leak.

[Marcoiv]

Thanks for the quick reply!
I need to post a proper introduction of myself and our rig.
We have a 2006 3684FL. Best 5th wheel or trailer so far for me. It has the living room up front with two slides there. I'm pretty tall so having the spacious bedroom and shower in the back is perfect. You don't see many of 5th wheels with that setup so I was glad to find this one.
Except for the damn black water problem. Small price to pay.

I guess you mean I should just go ahead and cut the plastic pipe, install the new valves (or seals) and then glue in a small section of pipe. Is that right? That might be the safest as I'm afraid all our push, pulling a prying might damage the surface between the valve and the tank (or pipe.). Its so darned close to being free we keep thinking we can just jiggle our way to freedom. However taking the time to actually cut the drain pipe may make the reinstall safer and more secure.
Thanks again!
Marc

[speedster100]

you should not have to cut any pipe, there is a lip on each side of the valve, a gasket on each side which sits in the lip. I suspect that the gasket is stuck, try using a small prybar or screw driver to separate pipe off of valve, once you get one side the other should come off relatively easy.

[Carl n Susan]

The 3" flexible no-hub connector used to join the two cuts ends of the sewer pipes uses hose clamps to seal. No gluing, no stressing the tank spud by prying on it, and facilitates the job next time (you do know it will happen again eventually?)


If you have to pry to get it out, you will likely have to pry to get it back in. That is when the gaskets get messed up and aligning the 4 bolts can be interesting.

With the pipe cut, you have the flexibility to install the valve cleanly and then attaching the downstream pipe thereby keeping the gaskets where they belong.

[kdeiss]

As mentioned above just use a screw driver between the valve and the flange the valve all you need is maybe a 1/4 inch of movement. I suggest putting a dab of Silicone on rubber gaskets before installing to keep them in place not rocket science I have replaced many. Getting the rubber gaskets in place is crucial otherwise you are going to have a leaker do not over tighten the bolts

[Marcoiv]

We'll have one more go doing that. Thanks for your reply.

[Marcoiv]

Looking ahead... that sounds like a good idea. Not sure where I can find one of those, but I'll check with our ACE hardware guys. They seem to have everything.

[Theunz]

I found that getting the valve back in required more room than removing it. I used a rachet strap to pull mine apart. As mentioned you only need about 1/4 inch. Just don't get heavy handed, there is not much flex to be had! Mike

[Marcoiv]

Ratchet strap... That sounds like a good idea. We only need another fraction of an inch in there. That way we don't need worry about gouging the interface. I thought replacing this valve would be a simple loosen the bolts, pull it out, replace it gig! Nothing's simple. Just glad the tank itself isn't the problem. We mistakenly pulled out two whole panels down there so I'm going to look closely at other maintenance we can do under there before screwing them back in.