I recently replaced a toilet's flush valve and spud (tank-to-bowl gasket). Now, water droplets form on right and left sides of unglazed underside of toilet tank. They must be from inside tank (as opposed to condensation) 'cause I put dye in the tank water and the droplets are the color of the dye. They don't appear to be from the bolts, as they're not near the bolts and the bolts were sealed with silicone, both inside and outside tank. The droplets are also not near the gasket. Someone suggested pinhole leaks in the tank. Could these have just appeared in this 17-year-old toilet tank? Or, what else could it be?

An errant valve spraying on the underside of the lid is a guess.


I do suppose that you have watched a flush with the tank lid off.

If that fails to show anything, wrap the tank with a paper towel and start flushing.

It is very common to sit tank onto the bowl incorrectly. Also water can be spraying onto handle hole... Do as KISS said. Remove lid and watch few cycles w/o the lid on...

Not a pro, but I had the same thing one time. Turned out I did not tighten the nuts holding the tank on sufficiently. Another turn or two... problem solved. Of course, it pays to not overtighten and crack porcelain.

I know exactly what your talking about, I believe the others are confused. I too discovered two little pin holes on the underside unglzed part of my toilett bowl. They are put there when the toilett is made and the clay is still wet so when the toilet goes into the kiln to harden it does not crack. They later fill the holes with a gob of clay so the toilet will no longer leak. I too have a toilet that is now over 7 years old and has just begun to leak from one of these little holes. I thought, at first it was the wax ring. But afeter pulling and replacing the wax ring THREE times with no success and thinking that I was just doing something wrong I tried a wax free toilet seal, the one that has the thick glue that holds it to the horn and then the seal inserts into the pipe and makes a leakproof seal. This too began to leak after a few flushes... not a bad leak but a leak non the less and just like the three times. Fed up, I pulled the toilet on last time and decided to do some further investigation. I noticed some, what looked liked, condensation under the bowl. I dried it and proceeded to run water through the bowl with my shower head. Sure enough a small leak started at one of the pinhole locations. The clay that covers the hole was slightly discolored around the edges and when I picked at it it just popped off and water began to leak out a little quicker. My next step was to fill the holes and reset the toilett. I wasn't sure what to fill the holes with... silicon, super glue, epoxy..? I decided to use super glue to fill the holes. While the glue was still wet I placed a piece of clear tape (packing tape) on top to help reinforce it then covered the top of the tape with more super glue. After drying I had a leak free, heavily reinforced layer of rock hard glue. I'm sure you can use a mirad of other things to achieve the same result. After replacing the toilet I am leak free!! Woohoo!! Good thing I didn't go out and buy a new toilett or keep driving myself nuts thinking there was something wrong with how I was placing the wax rings.

I totally respect what plumbers do... they must have an abundance of patience. I almost gave up and bought a new toilet but perservered through and found a solution that worked.

Cheers!

Hello Wright,

Welcome to the Plumbing website, Thanks for sharing your experience and to let you know the others are not confused they are experts and go step by step to resolve the issue.

John

Hi Wright...

Yeah, no confusion on our part... not if you reread the original question.

Here, confusedinVA is talking about a toilet TANK and a leak up at the toilet tank/spud assembly... not a toilet BOWL and the plugs they use to seal the holes as in your case. A toilet tank has 3 holes in it so they don't use the same plug method you are talking about for the toilet bowl. In fact, in most cases the holes you are talking about are "imperfections" and they get glazed plugs to fix the issue and get the toilet bowl to market... ;)

Good day!

Mark

Confused? Nah! Not us! We know the difference between a pinhole bowl leak and a tank leak. Wile you are correct about the manufactured Plugging pinholes you completely missed the boat on the question.
Clueless, As stated, You could be spraying water from the ballcock, Remove the lid and give it a flush to check. Other leaks could be cause by not tightening the flush valve enough,
Another could be caused by over tighting the tank bolts causing a small crack in th porcelain.
Tank bolts should not be cranked down tight. You need to let the tank "give" a quarter inch or so.
Then reason for this is if the tank's cranked down tight the first person who leans back will put a strain on the bolt holes that could crack the tank.
Hope this helps . Tom