Why does your rotor squeak?

Does your rotor squeek all the time, intermitantly, or only when braking? If the rotor squeeks all the time I would look at bearings or possibly something rubbing against the rotor. If it is intermitantly, it can be any number of things. Off the top of my head bearings going bad, shocks getting old and not traveling smoothly, something loose and a metal against metal rub, rotor out of true, need grease in tierod ends or ball joints, caliper hanging up. Squeeking when braking is usually no anti squeek or shims on disk brake pads. If you have not had your disc brakes checked in a while, your indicator may be squeeking to let you know your pads will need servicing soon. Have a certified mechanic take a look. Also the sound can travel such as your serpentine belt getting old and slipping. This will have the sound travel to the wheel well. You are driving along with the window open and swear that the sound is coming from the wheel well. Hope this helps G