Thanks for posting! The
21-150 Nylinder snaps on the hole in the door where the pin slides through so as to eliminate the noise of metal touching metal. I do not think it will help your pin move up and down; it should do that on its own.
To install the guide pin in a way that should serve its function, first remove the spring retainer and, holding the pin with spring, slide it through the hole in the door and lock it in with the retainer to keep from springing out.
If you have already tried this, or if you try it and it still doesn't work, it's possible that the
21-044 Benchmark Bifold Door Pivot with Clip is not the appropriate replacement for your original hardware. We may need to see a few pictures of your old pin in order to determine an applicable substitute.