There is a TINY little black-plastic piece as a component of this cartridge which is the weak link. The entire rest of the cartridge has functioned well for over 20 years. But when the handle grew loose, it was because a surprisingly important yet equally surprisingly chincy plastic piece finally crumbled. That thing needs to be made of better material.

I bought this several weeks ago. I just got around to fitting it. It works fine with no leak now. It’s a little tricky to fit us the first time, though the YouTube video did help. On that note, it would help if the presenter took it a bit slower and showed each piece, so that when he said something like “insert the bush”, we can see what he is referring to.

Kohler made installing the new valve easy. Simple and well engineered

The new valve arrived promptly and was easy to install. It works perfectly.

Easy to find the replacement part. Great guidelines from Kohler installation video from https://www.youtube.com/watch?v=gGY7UJQstj8. Successfully replaced to get rid of the leak in the kitchen sink handle