I have a 99 Grand Cherokee. I got new brakes and rotors installed a year ago. The dealership put on a 4 piston caliper on the front brakes instead of the normal 2. It was supposed to be better. Well I started hearing this squealing sound when I turn left (never when I turn right). I have a bumper to bumper warrenty so I took her into the dealership and the guy said the sound was from a little rust buildup on the caliper and it should go away. Well its been two weeks and it hasnt, I think its worse. Any clue what I can go back to them with? Thanks