Hey guys I am having a bit of an issue with my wife's 2012 prius. When braking between 40-60mph there is a weird rumble/rattle that I have not been able to figure out. It sounds as though it is coming from the front drivers side and I have already done a lot to try and single it out but to no success. I replaced the rotors and brakes thinking that they may be warped, rotated the tires, while the wheels were off, checked all of the link that could come loose, put the wheel on and shook it like crazy in all directions while I had someone under watch from behind, I even recently mounted a go pro to the wheel well while driving to try and find it, but I have found nothing and it is driving me crazy. Any ideas or anyone have any similar problem. I will post two videos on youtube with a link to them.
Braking at that speed is predominantly regenerative, but the transmission that handles that job rarely fail... But changing your transfluid would be a good way to investigate that. Of course without warning lights and errors codes you're trying to fix something before it's failed. I'd suggest a wheel bearing as another person has, but again that's a guess.
Except for the way it goes away with releasing the brake pedal, and slows down with the road speed. Longer recordings might be helpful ... maybe a friend in the car to deal with the phone.