I put the toilet back together, and it’s working perfectly.
Definitely mundane, but not pointless, I’ll share what I did to get it back to full operation.
I disassembled the whole stool.
It’s an elongated bowl, handicap height Gerber Powerflush toilet. That means it is longer, front to back than a standard toilet. This is important if you are a member of the half of the human with dangly bits. Every time I have to use a standard bowl toilet, my dangly bits encounter cold porcelain. That is very unpleasant. The handicap height bit means that it is just a bit taller, and you don’t have to sit down quite as far…or rise as much when you stand back up. As I’m 6’ tall, I have fairly long shins, and again - any time I use a standard height toilet, I’m thankful to my brother the Master Plumber (a state licensed skilled trade) who insists on installing this type of toilet.
I took the tank apart from the bowl, and replaced the Sloan Flushmaster in the tank. It’s held in with one large nut for the water outlet, and a smaller one for the water inlet.
I then removed the seat, and dismounted the bowl from the floor. And it is here that plumbers earn every penny they get paid. I put a rubber bath mat down in the tub to set the bowl on. It is heavy, it is slippery and…it is made of porcelain. You do not want to drop one of these.
The Flushmaster failed, but only as a symptom of something else. Here in Chicago, the water is pretty hard - a lot of dissolved minerals in the water. As the water passes through plumbing under pressure, you get a build-up of these minerals, aka “lime”. As I got the bowl down in the tub where I could pour out the remaining water, I was able to examine the waterways. These are the places where the water from the tank enters the bowl. The largest of them is right down in the bottom of the bowl, just as the waste exits the bowl. It is there the push the turds on their merry way.
In my case, it was completely limed up.
A saner man would replace the toilet, but he would also have to be a richer man. Following my brother’s advice, I got a two foot segment of 1/4" copper tubing and proceeded to dig the lime out of the waterway. Copper is ideal for this as it’s just hard enough to cut through the lime, but soft enough to not damage the porcelain. An hour or so of digging, and I had the waterway clear. There are also smaller water outlets in a ring just under the seat that washes away any waste that did not fall directly into the water. I cleaned those out with a stiff piece of copper wire - in my case, the center conductor from a piece of RG-6 coaxial cable proved ideal.
One other especially gross bit is turning the toilet over, and cleaning up the residue of the old wax seal. This is a ring of beeswax that sits between the floor flange and the bottom of the toilet. You also have to clean up the residue on the flange. You’re scraping out a mixture of beeswax and human waste, a job well worth at least $50 an hour.
After a through cleaning of the toilet, the flange, and the floor under the toilet, I set the new wax seal down, then carefully set the bowl down over the bolts sticking up from the flange. I sat on the bowl to seat the bowl, then finger tightened the nuts (remember porcelain). Then I put the tank to bowl gasket on the tank, and set the tank on the bowl. It has another pair of bolts that also get no more than finger tightened - but you can press on the top of the tank to make sure it is as tight to the bowl as it can get.
I re-mounted the seat, and tested the flushing mechanism. Success!