The Duramax is probably the most responsive to an aftermarket lift pump. The GMC and Chevy Duramax pick-up trucks do NOT have a lift pump to supply fuel to the engine. From the factory, the CP3 injection pump is the truck's only means of getting fuel from the tank to the engine. If you were to look at our video of “How the AirDog works” it will show you what happens when the CP3 pump pulls fuel from the tank to the engine. Therefore because the fuel is under constant suction it causes cavitation and excessive wear and tear on injectors and your injection pump. Also, this is the #1 cause of low rail pressure codes when adding aftermarket programmers or tuners that increase the demand for fuel. By providing both constant positive fuel pressure and 100% pure fuel to the engine, is where you get the added benefits of smoother and quieter idle, better throttle response, increased fuel economy, better mid-range through top end power and more consistent rail pressure to support both stock and modified engines.
Because we have a few different systems for the Duramax, install difficulty and times will vary. For example; The AirDog II, FP100 and Raptor pump kits do not require you to drop the tank to install the system. Because of our OEM style quick connect fittings and internal pump design on the AirDog II, you will simply hook the suction line to the factory fitting on the fuel tank sending unit. However, if you're going to install an AirDog FP150, this will require dropping the tank to install a 1/2″ suction tube. None of the Raptor kits require a suction tube to be installed.
As for the rest of the install, for fuel supply, all of the systems will either hook to the factory steel feed line that runs up to the engine or the line directly on the engine, we give the choice of hooking to either spot based on your mechanical capabilities. On the AirDog and AirDog II systems, the entrained air and un-used fuel will be sent from the system back to the tank through the fuel filler tube. Also, the factory fuel filter housing will remain in use when using any of the AirDog or Raptor fuel systems.
Many people ask why the AirDog II, with its higher flow rate doesn't need the 1/2″ suction tube. The reason for that is the way the AirDog II is designed internally. The AirDog II recycles fuel back through the base to keep the system constantly full, therefore returning less and making it a true “ON Demand” system. Also, all of the AirDog and AirDog II systems have a built in pressure port on the top of the base directly above the fuel filter, it's plugged with an 1/8″ pipe plug and can be removed and utilized to check pressure from.