2002 GMC Yukon Front Brakes

I tried removing the front brake caliper assembly to change the brake pads, but after removing the two bolts it wouldn't slip off the discs. Is there some kind of a safety pin the holds it on once the bolts are removed? The assembly was loose and I could slide it three-fourths of the way off, but then it gets caught on something preventing me from getting it all the way off.
Thanks.