Well Jack, I gotta wonder why you made the quantum leap to the wheel bearings. The W124's are famous for a life time of service from the fronts. Bearing noise (front) is not generally heard at low speed, unless the bearings are totally shot. It will get noisy as you approach 50-60 or so if you have a bearing problem. I would redirect to the issue you raise with brake application cancelling the racket. Start there. BTW is it from both sides or just one side?