Ford Repair Questions? Ask a Mechanic for Answers ASAP
I am not aware of any know issues with the 2012 Focus' with what you have described.
Did the grinding get louder when you lightly pressed the brakes to slow the vehicle?
If you would kindly rate my service as three stars or higher at the top of your screen, I can do an indepth search that will quickly give me any safety recalls, technical service bullitens etc...