diagnosing a mysterious internal toilet leak

[robGH]

Hello,

Glad I found this forum. My situation is this - I'm a commercial renter, and noticed that there was a squeaky and hissy sound emanating from one of the restroom toilets. There was also a slow steady trickle of water to the bowl. I asked the landlord to deal with it (since they've done it before and I had a similar problem with hissing/squeaking in the other restroom a couple years back), and they sent their plumber; I'm guessing he didn't want to be bothered, because he told my staff who were there at the time that he couldn't hear anything or see anything wrong. So I figured I would cut out the middle man and do it myself.

Things I've done -

• replaced the fill valve - that stopped the hissing and squeaky sound
• replaced the flush valve - complete with new flapper, etc.
• replaced the two bolts/washers/gasket sets that hold the tank in place
• replaced the gasket fitting over the flush valve nut that holds it to the tank - it was one of those that had two "wing type" flanges that extend out from it (like a TIE Fighter in Star Wars) that the toilet tank bolts threaded through
• replaced the flush handle mechanism - we've done this multiple times, as they're always breaking (as I said, commercial renter, customers just wear and tear things to death)

I did the dye test, and it does seem like there's a slight leak from the water in the tank to the bowl. Every ten minutes or so, the fill valve will run a tiny bit (about a second or two) and give it some more water inside the tank. The tank water level is sitting well below the top of the overflow pipe. I've tried adjusting the water level up and down, as well as regulating how much water was being allowed in from the valve in the wall. I adjusted the refill tube leading from the fill valve into the top of the overflow pipe. I thought it might be the flapper not closing properly, but if I reach into the tank and press down on it for an extended period of time, the water still slightly trickles to the tank.

I can't for the life of me figure out what it might be - all the pieces internally have been replaced (fill and flush valve, etc.)...the only two possible ideas that I might have is that in the process of replacing the flush valve, I didn't get it seated or attached or put back together with a tight enough seal somewhere with the gaskets. (I though everything was pretty damned tight, but maybe not?) Either that, or somewhere in the body of the toilet itself, there's a hairline crack or leak - I do notice that the water only leaks out from the top inside rim of the bowl on the left side, and the right side remains dry, but when flushed, water is distributed evenly on both sides.

Any help or ideas are appreciated. Sorry if the above is a long read - I wanted to give as much info as possible. Thanks!

 

[justin_dewan90]

Flapper, I like the korky black ones. Sometimes the ones that come with a new flush valve don't seal all the way.

 

[Geofd]

what brand is it...if you know....inside the tank there are numbers stamped into the inside back of the tank if you bring those numbers to a PLUMBING SUPPLY HOUSE they should be able to help you

 

[robGH]

Justin - I can see if I can find a korky. (That's the brand name, right?) But the entire flush valve was replaced already, including the flapper - would a brand new flapper be so leaky?

Geofd - I can't recall the name/style number at the moment; I did find the numbers, and ordered the proper part at a plumbing supply place. When I went a week later once they said it was in, they couldn't find it, tried to pass another part off as the one I ordered (different part number), then also gave me a different flush valve set once I told them it wasn't what I ordered. I walked out with two sets and his assurance that "they're all pretty much universal." I get the feeling he just didn't want to deal with finding the part that was ordered.

 

[robGH]

Update - the black Korky flappers at the hardware store looked to be lower grade than the other Korkys, so I ended up splurging a little and getting a No. 100 Ultra Korky "long lasting" universal flapper.

Just put it on the flush valve, and there's no change...I still have water slowly trickling into the bowl at the left side...

 

[Mikey]

Have you re-seated the tank on the bowl with a new gasket? (Not sure from your description of what you've done.) What's the brand and model?

 

[robGH]

Mikey - yeah, I had to replace the gasket - I made a joke about it looking like a TIE fighter from Star Wars, as it was a gasket with two "wing" that extend from the sides through which the toilet bolts are threaded. Pretty much everything in the toilet has been replaced that isn't porcelain.

 

[Mikey]

Weird. What kind of toilet is this? I'm no expert, but I've installed lots of toilets, and they all had big spongy gaskets, no wings.

 

[robGH]

This is the gasket style that I needed to replace.

https://www.amazon.com/Aqua-Plumb-C2732-Gasket-Eljer/dp/B01FF9MGPW

The tank sits slightly above the bowl "platform," so there's a gap which needs to be supported by these two "wings" on the gasket.

 

[Mikey]

Thanks. I do mostly Totos, no wings, but a much thicker and squishier gasket.

 

[robGH]

This one was on tight and pretty snug when I put it in. Plus the bolts are pretty snug, too, so I'm not sure how it might be leaking at that gasket level. My first inclination is that something isn't tight enough and that I have to disassemble it all and reassemble it.

However, my second inclination (as I mentioned at the start of the thread) is that there's some hairline crack somewhere. The water trickles into the bowl only on the left side, and not the right. (If you were to look at the bowl from above and imagine it as a clock face, the water trickle inside the bowl is only at the 6:00 - 9:00 side of the circle.) I wonder if it were leaking at the tank gasket level, if the water would be evenly distributed, rather than just leaking on the left?

 

[Mikey]

I wonder if it were leaking at the tank gasket level, if the water would be evenly distributed, rather than just leaking on the left?

If anything, I would expect most of the leak to be at the back of the toilet. As I understand, the water comes out of the tank, and flows into the circular channel around the rim, and then down the sides of the bowl. So, if it were a small dribbly leak, it wouldn't get very far toward the front.

 

[robGH]

That's what's weird - it's not at the back, but at the left side. If I shut the water off at the wall, and drain as much water as I can out of the tank, there's still a tiny bit of water that sits below the lip of the flapper. And it still will dribble into the bowl. I can't figure it out, other than there's a tiny crack or leak somewhere, or something isn't screwed on snug enough.

 

[Citywide Plumbing]

Thank you! very useful information!

__________________________-
Plumber San Francisco | Water Heater Replacement in San Francisco

 

[Mikey]

You could try squirting a small bit of colorant near where a leak might be -- I'd start with the left holddown bolt, maybe -- and see if it makes it into the bowl. Is the toilet absolutely level?

 

[TomFOhio]

Make sure your chain at the flapper is not to tight. If you see dribble going into the bowl it is the flapper assembly. You might
have to replace the whole thing again. If so get the fluidmaster kit that has the flush valve assembly and the fill valve that you can
use later on a different toilet if needed.

 

[TomFOhio]

Make sure your chain at the flapper is not to tight. If you see dribble going into the bowl it is the flapper assembly. You might
have to replace the whole thing again. If so get the fluidmaster kit that has the flush valve assembly and the fill valve that you can
use later on a different toilet if needed.

 

[TomFOhio]

Don't know why it went twice.