Hello, I bought my son a 2007 Tuscon, and it started acting up on him while away at college. Whenever he brakes, there's a sort of whining noise coming from the rear of the vehicle. Is sounds like maybe a hydraulic issue or something. It starts when you hit the brakes and lasts until about 10 seconds after accelerating again. It's not a grinding noise or anything like normal brake wear that I'm familiar with. Anyone have any ideas or have a similar issue in the past?