Upon further inspection, the nub that's supposed to protrude the piston is worn to nothing. I can't say whether it was my fault or if I bought them that way, but I prefer thinking I screwed up over thinking I got ripped off so we'll stick with that. The retainer clip was also a little loose, so I pulled it out & gave it a good squeeze, seems to be working much better now.

Now to decide whether to buy a rebuild kit for $25, or wait until Christmas to replace the front with an Elixir...