Does anyone know what mechanism provides detent to the plunger?
I see a lot of inexpensive "plunger caps" for sale.
EDIT: After a little searching it appears that the cap assembly is the detent. There are two parts. The threaded plastic part and a rubber grommet. I think the plastic provides the detent and the rubber cap applies the pressure needed to hold the detent.
I found a video that shows how you can "fix" the issue with a zip tie around the rubber grommet. I applied pressure with my finger and it improved the detent.
I'll try the zip tie trick. If it works I'm going to explore replacing the plunger cap.
Here is the video. (Some of you might find it entertaining.)
https://www.youtube.com/watch?v=XrrITUA7TlQ