Leaking value on toilet.

You must first specifically identify the leak. Then a specific solution can be found. What are your SYMPTOMS? Low tank level, low bowl level? Bubbles, in bowl, water on floor? Continuous inlet water flow to tank? More info, please.

Flush valve or fill valve, more details please.

Hi all

Joe, It's called a fill valve and it is probably easiest to replace it with a new fluidmaster toilet fill valve... super cheap (about $8.00), and very easy job for the average DIY person. I would suggest replacing the water tube to the fill valve with a new SS braided toilet supply tube... also cheap and will make installing the new fill valve that much easier!

Mark