[nitsuj]

I'm not pro like these other guys, but I offer a thought. With the calipers fully assembled, I'd think there are lots of places for fluid to hide. Even if you think you got it all out, I'd think you'd still have a few drops somewhere. The heat may be enough to make all the metal and rubber shift around and allow some fluid to dribble out and ruin the coating as it's curing.

Just a guess.