The problem is the same in each toilet: fills fine after flushing and the water stops normally. The water then slowly drains out of the tank until it runs ~ many times a day. I do believe this is probably my fault as I used bleach tabs in the tank for the first year.

I did research online and then replaced all the flaps myself. That seemed to solve the problem for 2 of the toilets, but not the other two. I then dropped the dye tabs into the tanks of the two still running and the dye spread almost instantly into the bowl. This indicates I have a rather major leak, yes?

More research leads me to believe I probably have leaking flush valves. I bought a kit to replace the entire valve, which involves a sticky rubber gasket to glue a new valve down over the old. I'm hesistant to install that.

Yet more reseach indicates I may be at the point where I need to replace the entire guts of the tank. Before I go that route I was wondering if anyone would be willing to give me some advice or feedback. Should I chuck in my project and call a plumber, or am I on the right track?

Thanks.

Make sure the water stays below the top of the overflow tube.

Clean the seat where the flapper rests on.

hendricus, I felt the seats for the flappers and didn't feel any rough edges or debris, but I didn't scrub them. I'll try that just in case.

I have the water level set about an inch below the top of the overflow tube on all the toilets.

Where should I go next?

I could easily see just a very little bit of water movement at the back of the bowl when they were leaking.

Maybe switch out a flapper from a good toilet and put it in a troublesome toilet. then you could safely assume it was the flapper if the good one happens to correct the problem.

I bought a kit to replace the entire valve, which involves a sticky rubber gasket to glue a new valve down over the old. I'm hesistant to install that.
I've never seen any glue involved with the replacement of a flush valve...but maybe mine is more typical than yours. If yours is just a typical one, I'd just take the one back that requires glue and get a different one. The last one I changed was all pretty well finger tightening of things...if my memory serves me correctly.

I too won't pay a plumber if it is something simple that I can do myself.

Sue

So I poked around in the tank a bit more last night. Scrutinized the process and I don't see anything amiss. Nothing's catching or rubbing or skipping. As soon as the tank is done filling I can hear the trickle sound of water leaking, though, and it never stops. When I reach in and push the flap down harder, the trickling stops. After I release it the seal seems to hold, so maybe this is just a flap issue (I'd love that).

When I bought the replacement flaps I went into the local Mom & Pop hardware store with my old flap in hand and told them I wanted the best they had. I ended up with bright red Korky flaps.

Since holding the flap tighter seems to stop the trickle, should I just start buying different ones to try, or is there something else I can do to increase the seal?

You need to reliably fix this. If your efforts with replacing the flappers are not working, then consider replacing the toilets. I realize that replacing a flapper cost only a few bucks and that replacing a toilet cost much more, but replacing a toilet can be a DIY project. You can buy some of the best new toilets on the market for a little over $100. They flush better and may use less water than the ones that you are replacing and sometimes the local water companies have rebates available that can help. Good luck!

Roland

Tomorrow I'm going back to specifically ask them to order more for me.

Thanks for all your help, everyone. I really was ready to throw in the towel and call the plumber.

I just came back to check on you and see if you got the problem solved. Congratulations! I hope DH was proud of you and the money you saved by doing it yourself.

Sue