My toilet runs after almost every flush. I have had the float and flap (guts) changed, but is continues. Should I change the whole toilet seeing that it is over 20 years old, but works fine otherwise? Will that help? What should I do?
Feesme

Hi feesme,

Some time the new flapper will not fix, but the valve it seats against can also be a problem. Feel it with your finger tip checking for nicks and crud. Smooth off with 3M pad or 00 steel wool. Worst case scenario it can be completely replaced for about $10 but a bit of work.

Check the flush valve. Most likely the new flapper is not sitting against the old flush valve assembly. We almost always replace flapper AND flush valve assembly at the same time to reduce chances of call backs!

Fluid master sells an entire tank replacement kit... includes all of the above plus a new fill valve for about $18.00 see the Image below.

I think that is the right way to go at this point. You can change the fill valve at this time, too and hopefully not think about your toilet again for a long time!