This Coolant Filter Kit for the 1994 to 1997 is not a new idea to the diesel engine world. They come in most OEM applications for medium duty and OTR tractor trailer rigs. The idea was somehow tossed aside for light duty applications, most likely due to cost. For our light duty trucks it is a very important issue that needed to be addressed. Many diesel engines - like the Powerstroke - are cast with sand in the process. This sand is NOT completely removed from the system. In fact, much of this sand leaches out of the casting over time. The sand wears away at water pump seals, hoses and radiators. Removal of this sand can greatly increase your water pump life. In addition to sand, there are other things that the filter is removing. SCAs, or supplemental coolant additives used in protecting against cavitation, often flake off the walls. This "precipitate" is a very abrasive particle - like a scale - floating around freely in the system unless caught by a filter.