As it said in the title: My vent's heat/cool blend door doesn't stick anymore! I had to pull my evaporator from its housing under the dash, and while I was there, I decided to snoop around a little.

I cleaned out a bunch of grime and gunk with my hand. I then found the blend door and noticed that the foam around the edges had deteriorated in certain areas. It had turned to a kind of sticky gunk. I removed the offending areas and now the door moves freely, like a brand new door would! It still seems to seal pretty tight, and most of the foam in the entire system was still pretty good. It was just a few spots that had gone bad.

If you ever lose all your freon, you mind as well spend the extra hour to remove the evaporator (and replace the expansion valve while you're there), clean it and clean out any problem areas inside - like gunky, bad foam.