So the wifes 08 2500 auto will not flat stop to the point it is spooky, we have had it at several tire shops and the dealer as well and every one say its ok So I am thinking either some one has put the wrong brake pads on it or maybe the master cylinder and the slave cylinder is going out. Any one got a clue were I should start?

 

Does it stop ok if you put truck in neutral when braking, or does truck try to acelerate while you have foot on brake? If yes then might have torque convertor going out. If no then possible brake booster issue.
Perform brake booster test to confirm proper operation.

 

Awesome! Thanks now I've got some were to start.