Bottom front caliper slider pin not sliding in smoothly

I was doing the seasonal relubing off my caliper pins and noticed the bottom front one not sliding nicely and only moving a little bit. First I just removed the pin, cleaned it up, used a dremel to smoothen it a bit and relubed and put back in (it was a tight fit). Only a minor improvement. It did seem like the pin was getting sucked in a bit. Then I removed everything including the mounting bracket, removed grease from within mounting bracket hole with a screw driver and shop towel, then sprayed in copious amounts of brake cleaner to remove anything else, put on a new boot, changed back over to the cleaned and relubed stock slider pin I had laying around (I had used the pins that came with the Legend caliper initially when I had changed to the Legend caliper last year). It was really difficult to push the slider pin in and once in, it still didn't slide freely. I don't recall there being any issues when I originally put in the legend calipers.

Any ideas of what may be the problem?

Thanks