RAM 2500 Van V6-239 3.9L Magnum (1995)
Brake Rotor/Disc: Testing and Inspection
The most common cause of brake chatter, vibration or pedal pulsations on disc brakes is a variation in thickness of the disc.
Excessive lateral runout of braking disc may cause a "knocking back" of the pistons, possibly creating increased pedal travel and vibration when
brakes are applied.