One problem related to brake grinding noise has been reported for the 2004 Toyota Prius. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Prius based on all problems reported for the 2004 Prius.
: the contact stated upon entering a highway at 60 mph, the vehicle accelerated rapidly. Brake pressure was applied, but the vehicle did not stop accelerating. Each time brake pressure was applied; there was a loud grinding noise. Although the cruise control was not engaged, the cruise control was manually activated in an attempt to stop the acceleration. With brake pressure applied, the contact managed to exit the freeway using the exit ramp. When the vehicle slowed, the park button option was pressed and the vehicle stopped. There was no further acceleration or grinding noise. The vehicle was towed to the dealer and is awaiting inspection of the problem. The consumer also stated, when she applied the brakes, the pedal became soft and went to the floor. Updated.