OP's problem probably doesn't have anything to do with brakes anyway.
My tire guy explained to me that they have a policy that when a car has over 180,000 miles on it the wheel lugs can stretch. So they require you to drive the car for 25 miles, return to the shop to have the torque re-tested, Drive another 500 miles and then return again to have the torque retested,
They put this requirement right on the receipt whenever I have the tires rotated.
All wild speculation of course as no one here knows what happened.