Leaky Toilet Repair

[gmchamplin]

We picked up our 5.0TA in October 2017, and sometime in the first year started noticing that the bath mat that we keep in the bathroom was occasionally wet. It didn't happen very often and we didn't worry about it. When the frequency increased I started paying attention, and decided that it was a leak in the toilet supply line that only happened when we ran the pump, not hooked up to campground water. (This led to an unproved theory that the pump produces higher pressure than the 40-50 psi allowed by my in-line regulator.)

I wasn't eager to work on the toilet, and had another leak under the kitchen sink that needed to be fixed, so I took the trailer into my favorite RV service center, Quality RV Service in Alvarado. They determined that the leak was around the crimped copper band connection on the supply line coming into the bathroom. They replaced this with a threaded SWV connection which solved the problem, and allowed for an easier removal/replacement of the toilet in the future.

The problem didn't stay solved. On a trip this fall we started to notice the leak again. Now emboldened by the removable connection, I decided to tackle it myself. After looking at Thetford problems on the internet I decided that the likely cause of the problem was a leaky flush valve. They seem to fail a lot. So I ordered a new one on Amazon, pulled the toilet, and installed it. After re-installing the toilet, I found the leak was still there. After two more rounds of remove, tighten connections, and replace, I decided I needed a new plan.

I had determined that the leak was not at the supply connection, but at the back of the toilet. I got some fittings that allowed me to hook a garden hose directly to the supply line with the toilet removed and accessible. I discovered that the leak was in the crimped copper band connection on the connector that attached to the toilet valve. In hindsight, I probably should have thought of that sooner. I replaced that connector with another threaded SWV connector and now believe the leak is really gone.

Lessons:
1) Crimped copper connections are not reliable with vinyl tubing.
2) Don't be afraid to pull the toilet,
3) Removable connections are better than permanent ones.

I'll post a few pictures.

[gmchamplin]

Replacement supply connection.

[gmchamplin]

Old toilet connector.

[gmchamplin]

New Toilet Connection.

[gmchamplin]

Other lessons:
4) It's a good idea to dump, rinse, and add deodorant to the black tank before pulling the toilet.
5) It is worth some extra effort to make troubleshooting easier.
6) I have the toilet shut-off valve, and never found a reason to use it.

[jadams]

Thanks so much for sharing your experience along with your nice write-up and pics. I'm sure it feels really good to diagnose what was really causing the leak and solve it on your own. I'm always interested in learning more about the different systems in my trailer. That's what keeps me coming back to this sweet forum.

[jadams]

Originally Posted by gmchamplin

Other lessons:
4) It's a good idea to dump, rinse, and add deodorant to the black tank before pulling the toilet.

Indeed!

[rubicon327]

Originally Posted by gmchamplin

This led to an unproved theory that the pump produces higher pressure than the 40-50 psi allowed by my in-line regulator..

You are probably right. The pump cutout pressure for the Shurflo 4008 typically used is 55 PSI. This of course could vary a bit either way depending on exact pump adjustments.

[canyonrider]

I also think that the pressure increases well beyond 50 psi when the water heater heats up from cold to full temp without any use of taps/toilet. In the two instances we have experienced water leaks, the leaks occurred when the water heater warmed up to the max temperature.

[rubicon327]

Gary: Sounds like you finally have it fixed. For future reference if you want to get rid of the vinyl line altogether (which personally I think is a weak design) you can use a SS braided flex that connects right to the toilet, goes through the wall and connects to your toilet shutoff valve. Several of us have done it.

https://www.homedepot.com/p/The-Plum...20-2/310336653

(And yes a faucet connector is correct. It is not the size of your typical home toilet connector)

[gmchamplin]

Originally Posted by canyonrider

I also think that the pressure increases well beyond 50 psi when the water heater heats up from cold to full temp without any use of taps/toilet. In the two instances we have experienced water leaks, the leaks occurred when the water heater warmed up to the max temperature.

I agree completely. The leak under the kitchen sink that I mentioned only happened under those conditions.

[gmchamplin]

Originally Posted by rubicon327

Gary: Sounds like you finally have it fixed. For future reference if you want to get rid of the vinyl line altogether (which personally I think is a weak design) you can use a SS braided flex that connects right to the toilet, goes through the wall and connects to your toilet shutoff valve. Several of us have done it.

Thanks for the idea. If I ever have to touch it again that's what I'll do.

I think the real design weakness was using the pex copper crimp on the vinyl tubing. Both ends ended up leaking at that joint.

[Kingfish]

Originally Posted by gmchamplin

Thanks for the idea. If I ever have to touch it again that's what I'll do.

I think the real design weakness was using the pex copper crimp on the vinyl tubing. Both ends ended up leaking at that joint.

This is most certainly what caused the leak in mine. As others have stated, you can switch to a standard stainless braided line using a 3/8" shark bite toilet valve for 1/2" pex and running the line through the hole into the bath.

This also gives you a very handy cutoff valve if you don't already have one. You will also need an adapter on the toilet from 1/2" ballcock to a standard 7/8" available on Amazon from 2 sources. BTW, one is $8+ and the other is $12+ for the exact same fitting, so be selective. As far as I know this is the only one available.

Also make sure to get 7/8" x 3/8" compression fitting and shark bite valve. If you get a 7/8 x 1/2" compression fitting it may not feed through the hole in the wall.

[rubicon327]

Originally Posted by Kingfish

This also gives you a very handy cutoff valve if you don't already have one. You will also need an adapter on the toilet from 1/2" ballcock to a standard 7/8" available on Amazon from 2 sources. BTW, one is $8+ and the other is $12+ for the exact same fitting, so be selective. As far as I know this is the only one available.

I’m confused with this adapter. I believe the faucet type stainless braid connector with 1/2” IPS fitting screws right on. I posted what I used in post #10.

[Kingfish]

Originally Posted by gmchamplin

Thanks for the idea. If I ever have to touch it again that's what I'll do.

I think the real design weakness was using the pex copper crimp on the vinyl tubing. Both ends ended up leaking at that joint.

Originally Posted by rubicon327

I’m confused with this adapter. I believe the faucet type stainless braid connector with 1/2” IPS fitting screws right on. I posted what I used in post #10.

I tried the 1/2" faucet line but could not get it to seal. Even tightened it with a crescent wrench as much as I dared to..... on a connection that should be only finger tight. I suspected that the rubber seal in the compression fitting was a bit different. If you had different results then maybe I was wrong?

[brroberts]

I too have had trouble with IPS fittings leaking with RV plumbing.

[Kingfish]

Originally Posted by brroberts

I too have had trouble with IPS fittings leaking with RV plumbing.

I couldn't determine whether its the shape of the seal or the consistency of the rubber. Since the faucet connection requires a wrench I suspect maybe the rubber is more dense? I was able to tighten the adapter and 7/8" line hand tight as designed.