How loose are we talking here? maybe your caliber isn't working correctly! have someone press the brake peddle while you watch to see if caliber is actually pressing pads against rotor.
If so then it sounds like for some reason caliber is releasing to far allowing to much of a gap. Its suppose to just loosen up enough so that there is a slight clearance between rotor and pads.
Did you install pads yourself? What did you use to compress caliber piston so that you could fit new pads on?