There actually is a little bit of play in basically all disc brake calipers. It can be a little disconcerting the first time you notice it, but if you take a close look, you can see they're designed that way. Basically there's a rubber bushing/sleeve around the mount bolts and through caliper, after a long time, this can wear out, but a couple years is unlikely. I don't know for certain why, but I assume since it's such a ubiquitous design, there's a pretty good reason. Maybe that play reduces the likelihood of lock-ups?
I'll post a video of mine in a few minutes.
Edit: our front brakes are a notable exception to that.
Last edited by USSENTERNCC1701E; 09-18-2017 at 02:33 PM.