[Vwdiesel] Loose brake pad

[mikitka]

I have noticed a loud rattle coming from my left front tire. On further
investigation I can see the brake pad moves a good distance up and down. I'm
not too familiar with the VW set up, The right side is good, just the left
side is really loose.  Is there a clip that either is broke or missing that
I can get to make the pad a snug fit?  The pads are like new still and the
rattle seems to be getting worse.  Also what size allen or wrench will I
need to take the caliper off, would help save me on guessing when I take it
apart.  

Thanks,

Nick