what causes vibration on the wheel when braking
Mis-torqued lug nuts, bent wheel, out-of-balanced tire are all causes of shakes when braking. Unless I missed it in your presentation and one of the most important tasks to prevent brake chatter or vibration would be to torque all the bolts including the wheel bolts. If the bolts holding the wheels to the hubs are not properly torqued they will cause vibration when you apply your brakes.