Flowmatic, 20+ years Shower Valve

I am trying to replace a Flowmatic shower valve. The number listed of the valve is 84086. The Big Box stores don't carry it here in the Detroit Area.

It would be be easier to install the same valve than put anew one in (and cheaper LOL). Give up the hunt and install a different valve?

The price phister flowmatic cartridge 900-022 is still readily available. Handle, especially the little star button, and trim plate, are getting harder to find. Replacing the whole valve involves having access inside the wall, from front or rear. For now, a new cartridge should fix your leak.