FASS stands for Fuel Air Separation System and is a combination diesel fuel lift pump and fuel filtration system that is designed to improve your diesel trucks fuel mileage, engine performance and extend the life of your diesel injection system. To insure we offer only the best performing fuel pump on the market FASS has chosen to manufacture our systems from American made components that are then assembled and tested in house by our highly trained and qualified staff. At FASS our first priority is to guarantee that only the purest quality fuel is delivered to your diesel engine. We achieve this by removing dirt, water and air through our two step filtration process while switching the fuel delivery process from a suction delivery to a pressure delivery, thus eliminating the possibility of reintroducing air back into the fuel after it has already been removed. With filtration being such an important process, we choose to use fuel filters that have a rating as low as 3 Micron, which provides superior protection from debris in your diesel fuel.