Crazy brake issue

[Joefishizzle]

Okay guys, so I've had this nasty vibration for a while. Changed my carrier bearing, u-joints, brake calipers, pads, ball joints, inner+outer tie rods, tires, alignment. And still.

So let me say this. The vibration comes and goes. I haven't been able to quiet figure out when and how so it happens.

However i have noticed that sometimes the brake pedal has alot more resistance at times. I've flushed the brakes thourouly, all fresh fluid. No leak, at brakes or master.
When the vibration does happen it gets alot more extreme when i brake. And continues until i brake enough or slow down to about 40 or so.

Some one please help me out here. The vibration is felt strongly through the wheel, pedals and front end and the wheel shakes ridiculously. My rotors aren't new, but they aren't warped or getting worn or hot spots by any means.