I have two guesses for you. The first time my F3 started to squeak, I had glazed the pads by running them too hard too fast. They didn't break in properly & formed a layer of crap that decreased grip and squealed. Sanded them down lightly with fine grit sand paper and they were fine. Second, (this is a guees) on cars that squeak, it is because of build up on the rotors, which need a quick sanding with a random orbital sander. Take the suggestions for what they are worth.