I have a 04 r1500 4wd. When I start from a dead stop--or backup I hear a moan from the truck. I believe it is in the brakes because if I put my foot on the brake pedal lightly the noise stops. I have replcaed rotors and pads and cleaned and adjusted the emergency brake shoes. Do you suppose its the calipers dragging? Should they be replaced? It has been happening on and off for about a year but is getting more annoying now.