Kia Troubleshooting Questions? Ask a Mechanic
Have you checked the thickness of the brake pads? Also, try using a screw driver to push back the dust shields behind the rotors and see if that helps it. It does sound like you probably have glazed rotors and pads that is probably causing your noise. The solution would be to either resurface or replace the rotors, and replace the brake pads. To prevent it from happening again don't ride the pedal the whole way down the hill, hit it for a few seconds and then let off for a few. This allows the brakes to stay at a lower temperature.
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Ok good luck, if you need pictures or anything just let me know.