Toyota Repair: Vibration in braking w/Tacoma, rear drums, tacoma 4x4

Question
I have a 2003 Toy. Tacoma 4x4 Dbl Cab

Bad vibration when braking at medium to hard pressure on brake.  Had rotors and front brakes replace and four new tires but the problem doesn't go away.  Seems to me it must be a design/engineering flaw in some parts or materials.  Any ideas?

Answer
I doubt if it's a design or engineering flaw because most tacomas do not have this problem, there is something wrong with either the parts that were replaced
or the repair procedure, I seriously doubt that this problem was there when you bought the truck so something must have happened to cause it.
The only thing that will cause a vibration when the brakes are applied is either that the front rotors are warped or that the rear drums are out of round, since the front rotors and pads were replaced along with the tires I would focus on the rear drums, they may need to be remachined or replaced.