Leak after dumping toilet

[WillBeaden]

After camping for four nights over the July 4th weekend, I closed down our 2006 2720 in the usual way. I heard the expected whoosh as I opened the dump valve on the floor at the front of our Thetford recirculating toilet; then closed up the camper and drove to the dump station. The fill gauge on the toilet had shown it never went past half full. I had used the blue Thetford deodorizer when charging the toilet.
As I hooked up the sewer hose at the dump station, I noticed blue water leaking out under the wall above the black water hookup. This is the first time I have ever noticed this, and we did not notice any leaks during the four days of camping.
Is the fault likely with the doughnut seal or something in the EZ-Slide valve, or something else?

[Shane826]

Ugh. Sorry that happened.

If it never leaked while you were camping then it sounds like EZ-Slide valve is working properly.

If it only started leaking when you were dropped the waste into the pipe and held it there en route to the dump station, sounds like the seal between the EZ-Slide valve and the floor has failed. TM likes to use gobs of silicone to form a seal back in those days. Try to find the actual Thetford seal instead. Part number 24304.

[Bill]

You can do a search on the Plumbing Forum for the term "foam donut" - that is the seal Shane is referring to. You need to replace it. A walk through the replacement process is in the Trail Manor Technical Library, here.

https://www.trailmanorowners.com/for...ead.php?t=5889

Several years after this tutorial was posted, Larryjb posted a link to a video of the same operation. While I don't necessarily agree with all the details, it is well filmed. Thanks, Larry.

https://www.trailmanorowners.com/for...ad.php?t=20467

Bill

[WillBeaden]

The 24304 part number doesn't come up on the Thetford site, but the parts diagram for the Slide-EZ valve shows 33364 Closet Flange Seal. It appears to be the new part number. Does anyone have experience with this one?

[Shane826]

Yeah sorry I missed that on the new diagram. Just be aware the recirculating toilet is discontinued and parts are getting hard to come by.

[WillBeaden]

Guess I better order two!
BTW, thank you for your help. Everyone is so helpful, and Bill's instructions are extremely detailed.

[Bill]

I may be a little confused. The B&W picture in Shanes's second post is titled "Slide EZ Valve". But the picture below the title shows a kit of parts, which includes not only the Slide EZ valve as Part 1 of 10, but also a bunch of other stuff. Among the other stuff is the Flange Seal, item 6. This flange seal is sometimes known as the "foam donut", and this is what has failed in your trailer. Your immediate need is to replace the "foam donut".

I believe that the "foam donut" is not Thetford-specific, but is used on many RV toilets, and is available at most any RV parts counter. If you take the Thetford part number to them, they ought to be able to cross-reference it. Notice that if you go to a hardware store or big box store, you will find a selection of foam donuts. These are sized for home plumbing, and will not work in the Thetford.


As for the Slide-EZ valve, the pair of gaskets inside the Slide-EZ valve fail occasionally. Thetford used to sell the pair of gaskets alone, and replacement is easy. So if you can find and buy either the pair of gaskets, or the entire Slide-EZ valve, you will be ready for future problems with the Slide-EZ valve. But what you need today is the foam donut.

There is nothing wrong with buying the entire kit of Thetford parts (if you can find one), but other than the flange seal, you don't need the other parts in the kit.

Confused yet? I do not believe that the Slide-EZ valve on your toilet has failed.

Bill

[Shane826]

I don’t believe the Slide E-Z Valve has failed either, as per my post. I agree with you that the donut has failed. I was just showing that Thetford has in fact printed two different parts lists for the toilet. The one with the handicap logo on it is the newer version.

Also when I removed my recirculating toilet there wasn’t a foam donut, just a pile of silicone.

[WillBeaden]

I got the toilet off, and the seal and surrounding was covered with silicone as per your experience. ...not even sure how it could ever leak with all that silicone, but I suppose it does harden a bit over (almost 20) years - assuming this is still the factory installation. There was no stabilizing disc; so I will make one of those.
One curious thing, however: one of the slide brackets for the wedge was bent, as if someone had tried to pry the toilet up (see attached photo.) Or perhaps force applied to the side; but it would have had to have been intentional.
Still, I had to apply a fair amount of force to the wedge to pull it loose, so I believe it was anchored pretty well. The other wedge bracket appears straight.
1.)What do you think? I could try to straighten it, but I don't want to mess it up.
In the second photo you can see that the left hand slide is straight.
2.)Should I spray a little silicone lubricant or silicone grease on the slide? It's pretty stiff.

Thank you. Great instructions, Bill!

[Bill]

To straighten or not to straighten? That is the question. You are facing one of those classic risk/reward decisions. The reward would be that you would have a straighter track, on which the wedge would slide more smoothly and sit flatter once in place. That would be nice. The risk is that if you try too hard to straighten it, you might break the plastic that the track is screwed into. That would be catastrophic.

If it were me - and of course it isn't - the first thing I would do is make sure that the short edge of the track is at a right angle to the bed of the track. Your second photo suggests that the short edge may be bent a bit inward, which will make it harder to slide the wedge into place along the track. I think you could bend the edge back by gentle application of a pair of pliers. If it won't go, don't force it.

The next thing is that the same photo shows that the bed of the track is bent outward, away from the long edge of the track. I think I would try using two pairs of pliers, one on each side of the bend, to ease the bed back into the proper 90-degree angle. This is where you need to be careful. Since the parts were strong enough to withstand the initial prying, I think you could do it. But again, if it resists, and you are uncomfortable, stop.

As for straightening the upward bend in the middle of the track? That would be easy to do if you could remove the track and work on it by itself. But I don't think you want to dis-assemble things that far. So maybe leave that as it is.

When you get ready to fasten the toilet down, the instructions specify a particular height for the two hex nuts. That height will no longer be correct on the bent side, so you may have to experiment a bit.

I see no problem with applying a very thin coat of lube on the track, but I think that once you get the short edge back into place and the nut set to the needed height, you will find it is not necessary.

Let us know.

Bill