The contact owns a 2012 Toyota Prius. The contact stated while driving 60 MPH, there was an abnormal grinding sound coming from the brakes while the brake pedal was depressed. The brakes, the traction control, and the ABS warning lights were illuminated. The vehicle was then taken to an independent mechanic where it was diagnosed with brake booster and master cylinder assembly failure. The vehicle was not repaired for the most recent failure. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 106,019.