My dad has a 1998 2500 totally stock truck with the Cummins, I took it for a drive the other day and when I turned the ignition on the pump on what seems to be the ABS pump'hydraulic unit" makes a really wierd sound? Sounds like it loads up and then loses pressure, hard to explain.

Just wondering if anyone else has heard this sound, is it normal? Not sure if we should be considering a new unit?



Thanks