I have an 07 mcs and the rear brakes are making a grinding sound. Im quite sure its the rears because i turned the car off on a hill and applied the parking brake until it made some grinding noises, released the parking brake and it goes away. The brakes were replaced 6,050 miles ago, but just to make sure there was no metal on metal contact, I took the rear wheels off to check. No metal to metal contact, no rocks lodged in there and they spin about as freely as a set of rear brakes should. My question is, has any one experienced this phenomenon? It started about a week ago as soon as the temperature dropped to right around freezing. I am thinking the pads become harder due to temps being so low because it sounds as if it goes away as the pads get heated a little. Thoughts? Any advice or knowledge will be greatly appreciated. Thanks.