Airdog II-5G 165 GPH Air Fuel Separation Lift Pump 98.5-04.5 Dodge 5.9L Cummins W/In-Tank Pump

Airdog II-5G 165 GPH Air Fuel Separation Lift Pump 98.5-04.5 Dodge 5.9L Cummins W/In-Tank PumpThe 98. 5 02 2nd Gen Cummins got a pretty bad rap over the years for failed VP44 injection pumps, many claiming it was one of the worst decisions ever made to mate this supposed failure prone pump on a Cummins powered Ram. Now, was it really the VP44's fault, or was the engine bay mounted lift pump really the culprit? In most cases, the failure of the low output lift pump causes the demise of the injection pump. And to make matters worse, they

The AirDog II-5G DF-165 draws fuel from the fuel tank through a 1/2” suction line to reduce the risk of cavitation at the pump. The fuel is then drawn through the water separator where 92% of water is removed per SAE spec 1488. It is then pressurized through a Gearotor pump and sent to the 2 micron fuel filter before it is sent to the injection pump. The air from aerated fuel, due to tank sloshing and engine return lines, is separated and sent back to the tank through the 3/8” return fitting. The excess fuel that the engine does not use is recirculated through the diaphragm regulator back to the suction side of the pump.
This specific AirDog unit is designed for trucks featuring the in-tank lift pump. For those unaware, all of the 1998.5-2004.5 Cummins powered Rams came from the factory with a block mounted lift pump. However, if it ever failed and had it replaced previously, it very likely was retrofitted to the newer design that actually placed the pump in the fuel tank. If you're not sure where your pump is located, simply "bump" the key, which will engage the pump, then listen whether the hum from the pump is coming from the engine compartment or the fuel tank.