I have an 15i LTZ 4wd with 14k miles. Front passenger brake is squeezing badly. I pulled the wheel off to take a look and the warning bar is rubbing the rotor. Also, the inside pad is about half the thickness 1/8" of the outside pad 1/4"+. From what I've read it's an issue with the caliper piston not retracting all the way. What else could it be? Has anyone else experienced this? Would this be covered under warranty?