I recently purchased an older home (built in the 50's) and I'm in the process of updating a bathroom. The toilet is an American Standard 4086 tank with a Sloan Flushmate. The toilet is in perfect working order, however we have a newborn baby and my wife can't stand how loud this toilet is when flushing. I'm fairly handy so I decided to replace the guts of the toilet (Fill valve, flush valve, gaskets, etc.). I used a Korky Water Wise Adjustable Fill Valve (No. 528Z) and a Korky 3" Adjustable Flush Valve (No. 5030). I reassembled everything, following the instructions for adjusting both the height of the Fill valve and the Flush Valve. Turned the water back on. The tank filled up and shut off as expected. So far so good.

Now the baffling part. When I try to flush the toilet, the flapper on the flush valve opens, but the tank doesn't drain. There are a few big "gurgles". The tank level does go down, but only about 2 to 3 inches after 30 seconds. There is no visible change in the level of the toilet bowl. This tank level change causes the fill valve to open, but since the flapper is still open, the water just keeps running, eventually shutting off as the level in the tank rises to kick off the fill valve. Still the flapper is open. So after 30 seconds, the tank level drops and the whole cycle repeats.

The good news is there are no leaks, but why is there no force behind my flush? I've rebuilt toilets before and haven't had any problems. The only new piece to this equation is the Sloan Flushmate. Is there something inherently different in the base of the 4086 toilet that is causing the problem? Any suggestions? Should I just pony up and buy a new toilet?