AirDog II-4G Fuel Air Separation System DF-165 GPH (A6SABC409)

$849.00 $739.00
(You save $110.00)
AirDog DF-165-4G
Note: AirDog II DF-165 GPH A5SABC109 has been Discontinued and Replaced by AirDog II-4G DF-165 GPH A6SABC409

AirDog II-4G DF-165 GPH A6SABC409 2001-2010 Duramax LB7, LLY, LBZ, LMM (Preset at 8psi)

The patented AirDog® II-4G has been quality engineered to remove entrained air and water vapor from diesel fuel. The result is a compact, long lasting, efficient, and quiet fuel system made with superior quality for your GM Duramax.

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AirDog II-4G Vehicle Applications

AirDog II-4G DF-165 GPH A6SABC409 2001-2010 Duramax LB7, LLY, LBZ, LMM (Preset at 8psi)

  • 2001 GM Duramax
  • 2002 GM Duramax
  • 2003 GM Duramax
  • 2004 GM Duramax
  • 2005 GM Duramax
  • 2006 GM Duramax
  • 2007 GM Duramax
  • 2008 GM Duramax
  • 2009 GM Duramax
  • 2010 GM Duramax

AirDog II-4G - 4th Generation Fuel System

Advancing the AirDog® Tradition with the 4th Generation Fuel System! The AirDog® II-4G system improves engine performance by:

  • Maintaining Correct Injection Timing
  • Eliminating Spray Pattern Disruption
  • Allowing for a Full Power Stroke and Complete Burn

AirDog II-4G Benefits

  • Increased Fuel Economy
  • Increased Power Output
  • Increased Torque Output
  • Longer Injector Life
  • Improved Throttle Response
  • Reduced Exhaust Emissions
  • Optimized Engine Performance
  • AirDog® II-4G also overcomes loss of power for diesel engines operating at higher altitudes.

AirDog II-4G Features


  • Dual Feed Gerotor Pump
  • Low amperage motor provides efficiency and endurance
  • Self-aligning motor requires less maintenance and reduces noise levels
  • Intermediate pump shaft seperates motor from fuel
  • Small & Compact: ONLY 7″L X 10″T X 3.2″W

AirDog® II-4G Installation Kit

AirDog II-4G Fuel Air Separation Systems Complete Installation Kits include the following, see the installation manual for complete details:

  • Relay Control Wiring Harness
  • Fuel Module Up-Grade (when required)
  • All Fuel Fittings Required
  • Mounting Hardware
  • 1/2″ Fuel Lines W/ OEM Style Quick Connect Fittings
  • AirDog® II-4G Bracket & Spacer
  • Plastic Ties
  • Installation Manual

AirDog Installation Manual

Click this link to visit the AirDog manufacturer website to view the Installation Manual

AirDog Replacement Filter Options


  • Replacement AirDog Fuel Filter 2 micron (Part Number FF100-2)
  • Replacement AirDog Water Separator (Part Number WS100)

Choose to add one Extra set of Replacement filters (Set: Qty 1 FF100-2 and QTY 1 WS100) from the drop-down menu selection to add the items to your shopping cart. Do I only have to use AirDog® filters? NO. You can cross AirDog® filters over to Napa, Wix, Baldwin, CAT and many others.

AirDog FAQ - Frequently Asked Questions

See FAQ-Frequently Asked Questions page for more information

What pump do I need for my truck?

AirDog® recommends the system most compatible with your current truck. AirDog offers free technical support to help determine the correct system for your current truck.

  • Horsepower and AirDog systems - Reference Guide:
  • AirDog 100 and AirDog II 100 units are recommended for Stock to 500 Horsepower. (Note: AirDog recommends the AirDog 100 or AirDog II 100 for customers who plan to keep their truck completely stock).
  • AirDog 150 and AirDog II-4G 165 units are recommended for 500 Horsepower to 800 Horsepower. (Note: AirDog recommends the AirDog II-4G 165 systems for Modified trucks between 500HP to 800HP).
  • AirDog II 200 units are recommended for 800 Horsepower and beyond.

AirDog II Fuel Air Separation System Featuring Demand Flow Technology


AirDog® II-4G is designed to operate at flows and pressures beyond the maximum requirements of the engine. It receives fuel under vacuum from the fuel tank containing entrained air/vapor, particulate contaminates and unknown quantities of water.

The fuel passes through the water separator which removes the large particulate contaminates that could damage or jam the gerotor fuel pump. The fuel, with only entrained air/vapor and tiny particulate contaminates remaining, then enters the fuel pump.

The fuel, now under positive pressure flow, enters the fuel filter. As the fuel passes through the filter media and the remaining particulate contaminates are caught and contained, the entrained air/vapor is also separated. Through the positive fuel air separation features of the patented AirDog® II-4G the separated air/vapor is discharged from the filter and back to the fuel tank through the Primary Air/Vapor Discharge Port.

The fuel passing through the filter media is now free of contaminates and power robbing air/vapor. At pressures and flows able to meet the needs of the engine, it exits the fuel filter through two passageways. First, the fuel for the engine, passes into the fuel pickup tube and on to the engine. Then, the excess fuel not needed by the engine recycles internally through the pressure regulator back to the water separator.



GM Makes and Models - Duramax Diesel

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 the 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 AirDog® has 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 the AirDog® 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, AirDog gives 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.

AirDog II-4G Diesel Fuel Systems

On Sale Today with Free USA Shipping Air Dog II-4G DF-165 GPH A6SABC409 diesel fuel system efficiently removes air and vapor from your diesel fuel improving overall engine performance for your GM Duramax

Contact the PureFlow AirDog® Manufacturer directly for Warranty Information at or call 1-877-421-3187. PureFlow AirDog® manufactures and supplies AirDog® Fuel Air Separation Systems and Raptor® high performance lift pumps for diesel pick-up trucks.

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