Cummins redesigned their water pump on these engines in and around our year, 2002. This pump has larger bearings and more coolant flow. Annually I remove the belts and spin the pulleys to see if I can feel a bearing problem, water pump was a bit loose. I figured this would also be a good time to do a cooling system conversion to OAT. Purchased the decal for the coolant tank for $.35 from a Freightliner dealer.   Photos;