Pesky Plumbing Leak

[Hitchhiker]

The last time out camping I noticed a little leak from under the toilet which is located above the storage area in my 5th wheel. The leak was running down the 3" black pvc line that goes into my holding tank. On first impression, I thought the leak was due to the toilet mounting ring located between the base of the toilet and the mounting flange. Tightening the nuts on the two brass closet bolts didn't stop the leak so I ordered a new Thetford toilet flange seal.

Yesterday was a nice day so I decided to install the seal that had arrived a few days earlier. After carefully installing the seal and testing for leaks, I noticed it still leaked. Making a closer observation of the leak by sticking my head and shoulders into the storage compartment and carefully observing it's source with a flashlight, I concluded the source of the leak was via the threads of the tail-piece that's threaded into the toilet's floor mounting flange.

I again removed the toilet to obtain access to the floor flange, unscrewed the flange from the floor and unscrewed it from the tail-piece. Looking it over very carefully for cracks, splits, etc. and seeing none, I carefully applied a thread sealer and reinstalled it and remounted the toilet.

Again, testing for leaks, I discovered it was still leaking from the area where I had just applied the thread sealer. So, I again removed the toilet and flange, re-applied sealer, and manged to screw the flange onto the tail piece tighter that before, all the way to the limit of the threads.

Thinking this would surely resolve the leak, I again tested and sure enough, the leak is still present.

Now I'm at a loss as to why that threaded connection would leak. There must be a fracture in the PVC that I can't or didn't see.

My next plan is to replace the floor flange and tail piece which will necessitate cutting the 3" black PVC down-pipe along with a 45 degree angle and gluing new material back in.

Unless someone has a better idea for a solution, I'll tackle that job as soon as I obtain the required black PVC materials to put it all back together.

I hate plumbing!

[Hitchhiker]

The last time out camping I noticed a little leak from under the toilet which is located above the storage area in my 5th wheel. The leak was running down the 3" black pvc line that goes into my holding tank. On first impression, I thought the leak was due to the toilet mounting ring located between the base of the toilet and the mounting flange. Tightening the nuts on the two brass closet bolts didn't stop the leak so I ordered a new Thetford toilet flange seal.

Yesterday was a nice day so I decided to install the seal that had arrived a few days earlier. After carefully installing the seal and testing for leaks, I noticed it still leaked. Making a closer observation of the leak by sticking my head and shoulders into the storage compartment and carefully observing it's source with a flashlight, I concluded the source of the leak was via the threads of the tail-piece that's threaded into the toilet's floor mounting flange.

I again removed the toilet to obtain access to the floor flange, unscrewed the flange from the floor and unscrewed it from the tail-piece. Looking it over very carefully for cracks, splits, etc. and seeing none, I carefully applied a thread sealer and reinstalled it and remounted the toilet.

Again, testing for leaks, I discovered it was still leaking from the area where I had just applied the thread sealer. So, I again removed the toilet and flange, re-applied sealer, and manged to screw the flange onto the tail piece tighter that before, all the way to the limit of the threads.

Thinking this would surely resolve the leak, I again tested and sure enough, the leak is still present.

Now I'm at a loss as to why that threaded connection would leak. There must be a fracture in the PVC that I can't or didn't see.

My next plan is to replace the floor flange and tail piece which will necessitate cutting the 3" black PVC down-pipe along with a 45 degree angle and gluing new material back in.

Unless someone has a better idea for a solution, I'll tackle that job as soon as I obtain the required black PVC materials to put it all back together.

I hate plumbing!

[RV Wizard]

Richard, What model of toilet do you have? Did you notice where the supply water connected any evidence of a leak at the ball valve; any staining or corrosion? What I am gettting at is it may not be the flange area or seal causing your problem.

[Hitchhiker]

Mike,

Thanks for the reply, it's a Thetford Bravura toilet.

There's absolutely no water on the floor and no stains.

When I had the floor mounting flange out I inspected the wood in the floor through the hole for signs of dampness. It's bone dry, the wood has never been wet. It only leaks when flushed and the results is in the storage compartment that the pipe is routed to.

The pipe that's routed through the storage compartment has a 45 degree elbow, angles through the compartment, another 45 elbow, and then down through the compartment floor into the black tank.

After pulling the toilet the second time, I observed very closely under the toilet from inside the storage compartment with a flashlight. It seems to be leaking around the threads of the tail-piece where it threads into the floor flange. The outside surfaces of the female NPS floor flange remains dry but the male NPS down-pipe that's threaded into it gets wet after each flush.

I get about a half a tablespoon of leak on each flush.

If there's a way water (or sewage) can get from another location of the toilet or supply onto the area I described then I'll re-evaluate replacing the floor flange. I really hate to cut out the PVC but that's the only way I can think of to fix it.

[RV Wizard]

Richard, if what you are stating that the outside of the flange never gets wet but the threaded pipe from it does leak it does sound like the flange &/or threads are the problem. Hopefully when you do redo the flange and drain it no longer leaks.

[Sunny]

Richard
I would just replace the floor flange first and try it, this would be easier than the PVC.

Tom

[Hitchhiker]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Sunny:
replace the floor flange first and try it.
<HR></BLOCKQUOTE>

Good point, Tom.

[Canuck]

Richard,
If you can get at the area where the leak is appearing you may want to try using silicone tape to seal the leak. This tape works very well and creates a water tight seal especially since the waste water is not under any pressure. This may be a faster and easier method of addressing your problem.
I hope this helps.
Canuck

[Hitchhiker]

Hey, I may have it fixed!

I placed a dry paper towel underneath to test for drips and then flushed it several times this afternoon. The towel stayed dry after about 30 -40 test flushes.

The only thing different today from yesterday when I gave up in despair is that the thread sealer has had almost a full day to set up and cure. As sticky as that stuff was, I'm surprised it'd need to cure before sealing the threads. It took 10-15 minutes to clean it off my fingers.

I'll be watching it real close on the next trip out , I'm skeptical that it's fixed.

[Sunny]

Richard
You have a little over 3 weeks to get it fixed.
See ya'll then.

Tom

[FiverBob]

I can see it all now - - Richard opens the storage hatch while we all watch. "Richard, what is that bucket nailed down to the storage floor in that strategic location? Are you trying to save something of value"?

[Hitchhiker]

I used the rig at the Appalachian Campers' fall rally in Hunting Island, SC and had no leaks!

Anyone need a slightly used bucket?

[Hitchhiker]

Confounded thing started leaking again while I was in Florida for two months. A couple weeks ago I pulled out the floor flange, the threaded tail piece, and cut off about 12" of the black 3" ABS that carries the waste to the black tank and replaced it all with new stuff.

On a recent 3 day trip to Pigeon Forge it seemed OK, no leaks and bone dry!

[RustyJC]

That's one of those things that make you go "hmmmm....."

I had a similar situation with the kitchen faucet in the new Mobile Suites. We kept finding water on the shelf in the cabinet under the sink. I tightened the supply lines. I tightened the hose line fittings to the spray head. I took the sink drain lines off and repaired a cross-threaded coupling nut. I tightened the packing in the supply valve to the icemaker. Every time I thought I had it fixed, only to hear Sandy call me with those dreaded words, "Rusty, there's water under the sink AGAIN!!"

I finally chased it long enough to find a few drips running down the supply lines from the faucet body. After disassembling the faucet to find all the O-rings and seals in perfect condition, I got mad, went to Home Depot to pick up a replacement (you won't believe what they charge for a brushed nickel-finish, integral spray head Delta faucet!!) and changed the thing out. Voila - no more leaks, and Doubletree RV reimbursed me for the faucet within a week.

Finally, life is good!!

Rusty