Mysterious leak at water fitting on toilet

[rgardjr]

So I have an intermittent leak coming from the fitting on the back of my toilet where the water line connects. This has only happened three times that I can recall. The first time it happened I assumed it was because the fitting was loose and I tightened it-the trailer was brand new and this was the first time I took it out. No leaks for a while, but around the third or fourth trip I came back to the trailer and noticed water on the floor. Looked at the fitting again, but it was still tight. I scratched my head and decided that I'd be more vigilant about turning off the pump when we weren't in the trailer. So this weekend it happened again. This was probably the 8th or 9th trip with the trailer, but I think I may have a reason. I flushed the toilet without the pump on. I went over to have a beer in my friends trailer and when I came back an hour later the water was there again. I have been turning the pump off when we're away from the trailer because I was worried about the leak. So I left the pump on all night and all the next day and no leaks. Can anyone explain why this fitting leaks when the pump is off and the toilet is flushed? I'm going to try and recreate this tomorrow to confirm that this is what is causing the water leak.

[norty1]

So you are without city water and turn the pump off before flushing? I would think that you would not want to do that because no water would be left in the bottom for a seal from tank oders.

No clue why it would leak.

I would try another test doing the same thing with the pump on as see if it leaks. What brand of Loo is it?

[michael.g]

We had an issue in our Greyhawk with the toilet leaking at the water inlet. At first it would only leak when the water pressure was high. Eventually it started leaking all the time. I put teflon tape on the fitting and tightened it up. Never had a problem again.

-Michael

[rgardjr]

Originally Posted by norty1

So you are without city water and turn the pump off before flushing?

I would try another test doing the same thing with the pump on as see if it leaks. What brand of Loo is it?

I didn't realize that the pump was turned off until I flushed. I'm not sure why I didn't turn the pump back on to wash my hands before heading over for a beer, but I now have publicly shamed myself. After wiping up the water upon return I left the pump on until I packed up and headed for home-around 30 hours. Zero leaks in this period while the pump was on. I'm going to try to recreate this to see if the flush with no pump will result in a leak.

[norty1]

I do that often when we are just going in the rig to check something. I have had a Thetford and a Dometic. Never had that problem.

[rgardjr]

Just noticed my spelling of mysterious in the thread topic-oh the shame.

[norty1]

Originally Posted by rgardjr

Just noticed my spelling of mysterious in the thread topic-oh the shame.

Fixed

[rgardjr]

So I was unsuccessful in recreating the problem. So I decided to disconnect the water line from the toilet. It looked like the fitting was slightly cross threaded from the factory. Before I unscrewed the fitting I wiggled the hose and I was able to make water leak between the black threaded piece and the white elbow that the water line clips on to. The water hose is pretty rigid and doesn't have much play. So I disconnected the water line and pulled some additional line out to get a little play in the line to make getting the threads started correctly easier. I got it pretty tight and wiggled the water line and got a little click out of the fitting. I'm hoping this was the elbow properly seating itself into the toilet side fitting. I then tightened the black fitting down as tight as I can using my hands. I wiggled the hose and didn't get any water leaking like before. Hopefully this is the end of the mystery.


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[norty1]

Can you feel that hose when the pump is running feeling for vibration?

Whatever, it's fixed!

[mikefos]

Originally Posted by michael.g

We had an issue in our Greyhawk with the toilet leaking at the water inlet. At first it would only leak when the water pressure was high. Eventually it started leaking all the time. I put teflon tape on the fitting and tightened it up. Never had a problem again.

-Michael

I did this same thing w/ our old Thetford Aquamagic toilet and it solved the problem. Hasn't happened yet w/ our new Dometic 310.

[John H]

Did you happen to notice if the fitting had one of those ½’’ cone washers?

[mikefos]

Originally Posted by John H

Did you happen to notice if the fitting had one of those ½’’ cone washers?

I didn't notice, or don't remember, as it was a long time ago, sorry.

[John H]

Originally Posted by mikefos

I didn't notice, or don't remember, as it was a long time ago, sorry.

I was wondering if maybe the washer was the cause of the leak.

[mikefos]

Originally Posted by John H

I was wondering if maybe the washer was the cause of the leak.

Could be. I know when I disconnected my water pump for the winter, and then reconnected later, one of those washers fell out during disconnection and I didn't notice and it leaked like sieve. That would be an easy thing to replace and try.

[John H]

Originally Posted by mikefos

Could be. I know when I disconnected my water pump for the winter, and then reconnected later, one of those washers fell out during disconnection and I didn't notice and it leaked like sieve. That would be an easy thing to replace and try.

It’s worth a try for sure. I had very small leak at the hot water tank connection and that was the problem. I finally found the washers at an RV dealer.

[DMRGMC]

From the picture it looks like the supply hose needs to have more of a 90* angle down to the floor to keep the stress off of the plastic threaded coupling. That might be distorting the coupling and allowing the leak. You pulled out extra hose and the leak stopped. I would get enough hose out to create more of a ninety and then put a donut, using a clamp or tape, around the hose or clamp it in place preventing it from retracting in to the wall from vibration of traveling or foot steps, in order to make sure the tension is off the supply line.
If you cant pull out more hose then extend it on the outside of the wall making a loop to keep it uncluttered and any tension would be avoided.

[Rustic Eagle]

Originally Posted by John H

Did you happen to notice if the fitting had one of those ½’’ cone washers?

Doesn't take much to compromise the effectiveness of those rubber cone seals...., IMO they are designed to compress/seal properly just once.

I keep a few spares on hand....., and have replaced a few over the years to address minor leaks.

Bob

[Macshane43]

We have a similar problem with our toilet. At first we thought it was the shower water running along the wall to the floor. Found that it was leaking at the 45 elbow on the toilet water line. Earlier in the year we thought we resolved the issue by putting a water regulator on the city inlet. Then this past weekend, it leaked again. I have no idea why.


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[Rustic Eagle]

Originally Posted by Macshane43

snip....Then this past weekend, it leaked again. I have no idea why.

Check the condition of the rubber cone seal in the connector elbow.

Bob

[rgardjr]

Originally Posted by Rustic Eagle

Check the condition of the rubber cone seal in the connector elbow.

Bob

I don't remember seeing one when I took mine apart. I'll have to take another look and see if there is one there.