Micro-leaks in Tetford RV Toilet Water Entry Assembly

[pnichols]

For the second time in 10 years the plastic molded water entry valve assembly screwed onto the back of our RV's Tetford toilet has developed super fine cracks in the valve's plastic assembly that leak fresh water onto the floor whenever the 12 volt fresh water pump is left on. Since there is no water shutoff valve just for the toilet, the RV's entire fresh water system has to be shut down in order to stop water from leaking from this failed plastic part.

The first time I replaced it, the new plastic assembly from Tetford was a different material (black plastic) that I assumed was an improvement for reliability over the original assembly's teflon colored plastic material. I was wrong - it happened (micro crack leaks in the molded assembly) again on our recent trip.

The micro cracks in this molded assembly are probably "caused" by the toilet's slight vibration motions when traveling - combined with the stress that the incoming stiff PEX water supply line places on the the assembly due to the stiff PEX line being bent in a curve just before it is screwed onto the valve assembly.

Have any of you experienced this?

Is there a permanent solution so this never happens again? i.e. How does one install a small length of very flexible water supply line between the female connector on the end of the fresh water PEX line and the mating male connector on the Tetford plastic assembly so that that a stiff incoming line doesn't stress the molded plastic valve assembly? So far I'm finding that interfacing PEX line connectors to other connector types is not all that easy to find adapters for.

[hawkeye-08]

Reminds me of a guy with a truck camper that always told me, no reason for RV antifreeze, just blow the lines out and it will be fine.... He showed up at a group campout two years in a row with a badly leaking toilet and his wife was furious (they had to walk to the campground facilities instead of using the ones in the truck camper). His toilet valve froze and broke, twice. The next year, they had a travel trailer... I think he uses either a better winterizing blow out procedure or uses RV antifreeze now... I laugh out loud when I am winterizing our trailer and get to the toilet, it has been a number of years and it still reminds me of that guy being so stubborn.

Not saying yours was caused by freezing, yours sounds like it is caused by stress with the plumbing. Hopefully you can make some changes and eliminate the stress (and add a shutoff to help in case of future problems).

[happycamper002]

pnichols wrote:
S.G. right you are!

Maybe that's why I have toilet problems ... I've been putting Tetford parts. . . ..

LOL!!!

If that were the case Thetford would have sued Tetford for copyright infringement.
They do sound pretty close. Hehe!

[pnichols]

S.G. right you are!

Maybe that's why I have toilet problems ... I've been putting Tetford parts on a Thetford product. :B

P.S. Perhaps if others in the past before me had already grilled Thetford CSR's on this cheap part issue I wouldn't have to now.

[SoundGuy]

pnichols wrote:
I'll call Tetford tomorrow and try to find out what's going on with this part.

Pity the poor CSR who tskes this call. :R.

Regardless you'd probably have more success if you call Thetford. :W

[pnichols]

Well ........ guys, guess what: I just minutes ago disconnected my leaking Tetford toilet fresh water inlet valve from the toilet bowl and then pressure tested it with the water pump turned ON and the water line still connected to it. Removal took about 20 minutes using a headlamp and a mirror - no toilet bowl removal necessary (the same approach I used the first time 3 years ago with the first failure).

There it was -> an ultra-fine spray/mist coming from an almost invisible hairline crack within the rim of the plastic male connector that the incoming water PEX line male connector screws to. Just like last time with the original water inlet valve assembly!!!

Remember - I mentioned earlier that the replacement valve assembly that I installed 3 years ago used a different material (black plastic) for the plastic male connector that the incoming water PEX line male connector screws on to ... AS IF Tetford was trying to address a material failure problem at that time. The original plastic male connector on the original valve was a yellow-white color - looking like it was teflon.

If Tetford was trying to fix this issue of micro-cracks with a material change ... it didn't work ... and our recent RV adventure to Utah and Colorado suffered because of it.

I'll call Tetford tomorrow and try to find out what's going on with this part.

I wonder how many other RV'ers have a failed toilet inlet water valve like this and don't realize it because the drops of water from the ultra-fine spray merely drops directly down and out a crack onto the ground without wetting the floor around the toilet enough - or at all - so as to even notice it? (They may not be paying any attention to the occasional burp from their water pump while this is going on.)

[hotpepperkid]

pnichols wrote:
I also have to order a new valve, remove the old valve, and install the new valve. This is a VERY DIFFICULT job because of the close quarters in behind the toilet. I have to go pretty much by feel, use a mirror, and use a headlamp for light. I refuse to remove the toilet just to do this, even though it's difficult ... as that would be even more of a nightmare task.

Wow are one of those people that will take hours to get out of a job that would take 10 min to do. We have them at work

[hotpepperkid]

I have a similar but different problem. That little valve leaks after I turn on the water heater. After the water gets hot I turn on a cold water faucet anywhere there is quite a bit of extra pressure for an instant and then no more leaking

[westend]

I'm curious ... for those of you who installed an RV toilet shutoff valve in your rig - why did you do it?

I have valves on all the supply lines. In the event the toilet leaks or a sink fitting breaks, anyone can shut off that supply line and the remainder keep working. I think you found the value of that, previously.


The liquid around the plumbing was from soap spray during the air testing of the system.

[happycamper002]

'm curious ... for those of you who installed an RV toilet shutoff valve in your rig - why did you do it?

So far none of you have reported leaks from your RV toilet fresh water inlet valves due to them developing hairline cracks in the plastic material. Am I the only one to notice this manufacturing/design flaw?

------------------
That's exactly what happened when I decided to replace the toilet. Hairline cracks can develop by overtightening the fitting that goes into toilet. It could create stress on the threaded port opening.

It doesn't matter whether you are using metal or plastic fitting. Over a period of time plastic shrink. It's because of this "phenomenon" that things like this develop.

I installed a shutoff valve because the DW wanted a "bidet" like we have at home. Thetford calls it "extended hose rinse" feature or something like it. It tees off after the valve before going into the toilet port fitting.

Picture a hose rinse in your kitchen sink. European hotels have this in all bathrooms.

[pnichols]

Chris Bryant wrote:
have seen this failure, but I suspect it is due to stress on the valve from misaligned inlet tubing.

Chris ... I think that is EXACTLY what's going on in my situation.

The stiffness of the PEX - combined with it's non-aligned-angle attachment to the plastic fresh water valve's male connector is what I think is causing the stress cracks in this complex and (overly) deicate molded plastic Tetford fresh water valve assembly. The leaks in my valve assembly are so micro-small that the leaking fresh water is exiting not only as very slow drops ... but as vaporized water! I can see white vapor smoke escaping into the air around the valve assembly while the water pump is pressurizing the lines!

Not only did Winnebago angle the incoming PEX line less than ideal, but I feel that the Tetford valve design is not really the best from a reliability standpoint. As I said earlier, it looks like the valve supplier changed the material type between my original and first replacement valve assembly - but it's still not optimized. Brass or stainless steel would probably be the best valve materials ... but the valve's necessary design is most likely too intricate for metal forming.

I guess that a 3rd plastic Tetford valve, a short piece of fexible tubing, and a shutoff valve is my best choice right now ... but I hate the downsides of a piece of maybe less long-lasting pressure tubing combined with the additional leak potential introduced with another valve in the system. A better PEX entrance angle might be an even better fix, but that means punching a(nother) large hole in my RV's bathroom wall.

Ultimately, I'm probably paying the price for a toilet in the rear of a small Class C motorhome on a stiff E450 chassis driven too much on rough roads.

[SoundGuy]

pnichols wrote:
How would a Tetford RV toilet removal/reinstallation be any different (other than the toilet being lighter in weight) than a residential one?

RV toilets, including Thetford use a rubber seal not wax as you would use with a residential toilet.

So far none of you have reported leaks from your RV toilet fresh water inlet valves due to them developing hairline cracks in the plastic material. Am I the only one to notice this manufacturing/design flaw?

Here in northern climates where winter temps drop well below freezing finding a cracked toilet water valve isn't uncommon at all ... my local dealer sells dozens of replacements each season when an owner discovers the winterizing job they'd done wasn't so complete after all. I've never heard of one stress cracking but hey, anything is possible ... just replace the valve, add a flexible braided line to the PEX so you don't have to deal with this again, and move on. 🙂

[Chris_Bryant]

Thetford uses a sponge rubber seal- slips over the "horn" of the toilet before reinstallation- no chance of misalignment. It is included with the water valve.

I have seen this failure, but I suspect it is due to stress on the valve from misaligned inlet tubing.

[pnichols]

I've removed and replaced toilets in my residence while we were building it. A new seal is required when reinstalling. I always bought a couple of seals for the reinstallation process because any distortion/squashing of the seal while replacing the residential toilet necessitated lifting the toilet back off and trying again - with another new seal.

How would a Tetford RV toilet removal/reinstallation be any different (other than the toilet being lighter in weight) than a residential one? I am trying to avoid going through that again with our RV toilet in order to replace the plastic valve assembly mounted on the back of it.

I'm curious ... for those of you who installed an RV toilet shutoff valve in your rig - why did you do it?

So far none of you have reported leaks from your RV toilet fresh water inlet valves due to them developing hairline cracks in the plastic material. Am I the only one to notice this manufacturing/design flaw?

[SoundGuy]

pnichols wrote:
I also have to order a new valve, remove the old valve, and install the new valve. This is a VERY DIFFICULT job because of the close quarters in behind the toilet. I have to go pretty much by feel, use a mirror, and use a headlamp for light. I refuse to remove the toilet just to do this, even though it's difficult ... as that would be even more of a nightmare task.

You sure are insisting on turning this simple task into a monster it need not be. :S Turn the water off, undo the two flange bolts securing the toilet, and lift it out so you can work with it on your workbench. It's only a "nightmare" if you make it one. :R