Expensive toilet leaks from bottom of bowl

When I was much younger and didn't need to sleep a lot I joined up with a group of guys who renovated homes and sold them for a profit. I've probably installed three or four hundred toilets, so I thought I could help a friend with his leaky toilet. This is not your plain white $69.95 piece of junk. My friend's master bath cost a small fortune. The sink, toilet, floor tile, and shower are all color matched.
Here's the problem. A small amount of clean water was oozing out from the bottom front edge of the caulk that seals the bowl to the floor tile. I could not find any visible cracks in the bowl. I decided to try using a bright orange dye. I dumped out the cleanser from one of those bottles that people hang inside their tanks. As the water level rises and falls in the tank some of the cleanser is released from the bottle. It's suppose to keep the bowl clean. (It doesn't work, of course!) I mixed the orange dye with water and filled the bottle. I told my friend to call me again after the toilet had been flushed a few dozen times. Maybe we could spot some of dye on the outside of the bowl if there was a hairline crack. We found nothing.
I pulled the toilet and flipped the bowl upsidedown. Again, the bottom of the bowl looked very good. The only thing left on the list that could cause a leak was the wax ring or the floor flange. Because I was in the home renovation business for several years, I've seen plumbers use every trick in the book to assure that a bowl mounted to an uneven floor will not leak. They use double or triple wax rings, or they take several pounds of plumber's putty and create a donut around the bowl horn. The idea is to seal the bowl so completely that it could never leak. I've seen these "tricks of the trade" fail too many times.
I thought I had died and gone to heaven when a company called Fernco developed a flexible rubber connector that always makes a leakproof connection between the bowl horn and the floor drain. All the problems of uneven bath- room floors, damaged flanges, etc., are irrelevant with this ingenuous flexible connector. For a 3" drain pipe you buy Fernco #FTS-3B. I've used it at least a dozen times with perfect results.
My friend's very fancy and costly toilet is still leaking. This problem is a real mystery! The water that oozes from the bottom of the bowl is never more than an ounce or two. It is not continuous. Weeks can pass with no leaking at all! Once the leaking starts it usually continues for several days. A plumber would have no patience with a problem of this sort. Naturally, he would suggest junking the toilet. I asked my friend to contact the factory and find out if he can get an exact replacement. His wife would be very angry if we installed a new toilet that did not match the rest of their master bathroom!
I hope someone can think of something I haven't tried.
Thanks guys!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I can only think of two things that might be causing this.
The first is the seal at the bottom. Have you tried one of the new waxless seals that take the place of the wax rings ? That's all I would ever use. You have to make sure that it seals properly in the PVC that it was designed for--must go inside. I use the ultra seal brand and they have a detailed instruction guide on their site.
The second is not that common. If the temperature of the water going down has a spread (difference) of the outside temperature (dewpoint) then it might be sweating on the inside. I know this usually happens on the tank but this is a possibility. I once saw someone solve this problem by stuffing insulation inside the bottom open spaces.
All this assuming there is no crack which you seem to have ruled out.
J
h snipped-for-privacy@hotmail.com wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Prop the john up onto a box or platform, fill and look for leaks. It will be out of commission for a day but this should settle any questions. You may need to connect a water source in case there is any relationship.
Unlikely but plausable: Water is leaking from the bottom of the tank seal and running along the outside surface and draining into the bolt hole. Condensation on the outside of the tank is doing the same. Poor venting or partially clogged drain occasionally allows water to stand against the wax ring inside the drain.
Likely: A hairline crack is concieled and occasionally opens or closes due to the weight or position of the user. Clean water indicates it might be in the path to the ring of holes under the rim. Dye might be too dilute to see. Try UV dye and UV lamp. Much of the water that flows here does not sit in the tank first.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
replace the bottom of the toilet, the commode bowl. or run a lighted toilet cam thru the base and look for a cracked trap internal to the toilet. you've covered everything else. other factors related to the crack leakage include temperatures and weight of occupant or visiting occupant. other toilet stuff for others at: http://www.toiletology.com/frequent.shtml
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
clipped

I'm no toilet expert, but a fairly good detective. How about filling bowl and tank, separately, with vinegar and then testing pH of leak? Dye probably too dilute to be sure. Can the drain have a minute crack, and sewer back pressure cause leak occasionally?
We had odd behavior of one toilet before the whole sewer pipe for our condo backed up into our condo, it being between sewer main and all other units. A gurgle once in a while, for few days, then bath #1 toilet with puddle around base. Toilet #1 won't flush, so used toilet #2, it backed up and ran over. Obviously, our toilets didn't decide to plug up at the same time, must be sewer line. Called city (Sunday evening, of course) to see if any reports of trouble downline, as the area has long history of sewer problems and recent replacement of a pump downline. Nope, says the city. Call plumber, rotoroots out all the way to city main. Replaces wax seal and adapter thingamajig on our toilet #1. About a week later, the city is digging up sewer directly across the street from our condo. Seems to me that the city main plugged and backup pressure or pressure from other units in condo blew the seal on our toilet #1.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

If pressure from the sewer main is affecting the seal on your toilet, then you aren't vented correctly.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I really appreciate all your thoughtful replies!
Joey, I have tried some of the waxless seals. I suppose the most popular ones are made by Fluidmaster, since they have a virtual monopoly in Home Depot and Lowes.
Here's why I'm completely sold on Fernco's flexible horn to drain connector. As long as the bottom of the bowl is smooth and clean the connector bonds to the bowl flawlessly. It uses an elastomeric adhesive that is incredibly strong and very flexible. You can lift the bowl off the floor by the connector five minutes after you press it on!
The Fernco connector has two flexible ribs that lock firmly inside the drain pipe. If the bowl is not close to the wall you can literally spin the bowl around in circle and not break the seal! Try that with any other type of seal and you'll end up with a flooded bathroom. Just to prove to myself that this connector would never leak, I once shoved a block of wood under one side of the bowl so that the entire bowl was tilted and the connector was not fully pushed down into the drain pipe. I took a garden hose and ran thirty or fourty gallons of water through the bowl. That Fernco connector still did the job, even though I did everything I could to screw it up!
By the way, I have no relationship whatsoever with Fernco.
Thanks again guys. I'll give some thought to all your suggestions.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
clipped

it? Running slow or gurgling? All seems normal and this was about a year ago. How does one check the sewer vent in 2 story building?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.