I just bought a 2003 gmc sierra 2500 crew cab and I notice the brakes giving me a pulsating feeling when stepping on the pedalwhile stopped, and keeps going on while holding the pedal down while at a light, but seems to brake fine. This is not noticed while braking to slow downwhen you feel a warped rotor.I also get the same feeling when youturn the wheel slightlywhilestopped. Any ideas this is a 8.1 with the allison thanks Kevin