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aFe POWER DFS780 Diesel Fuel System - Dodge Cummins


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The diesel fuel in your truck contains contaminants, water and air/vapor which is reducing power and damaging your diesel fuel injectors. Introducing the aFe POWER DFS780 Diesel Fuel System, with its patent-pending design capable of removing power-robbing entrained air, water and contaminants. The DFS780 also boosts fuel pressure ensuring constant availability for the high-pressure transfer pump, improving throttle response and horsepower at all RPMs. 


The DFS780 was designed from the beginning to eliminate weaknesses found in other "fuel transfer" system. aFe has spent almost four years engineering what we feel is the best, most reliable system available. Depending on the specific application, we offer features such as boost-activated fuel flow increase, a high-impact polycarbonate "sight glass" to visually check fuel conditions, a reliable "marine grade" motor and Viton seals to name a few.

Quick Features and Benefits:


  • Clear high-impact polycarbonate sight glass allows visual

     inspection of fuel

  • Helical bronze spur gear pump design runs quieter than

     straight cut gears

  • IP56 Marine Grade (protected against dust intrusion and

     powerful water jets)

  • Contoured CNC machining of manifold passages enhances

     flow to reduce pressure drop

  • 1/8” NPT fuel pressure gauge port

  • Viton seals which are compatible with most diesel and

     biodiesel fuels

  • Typical installation time is two hours

     (plug and play - no modifications to fuel tank)

  • Completely reversible - No damage to vehicle

  • Built in the U.S.A.




To ensure the quietest operation possible, the DFS780 uses Helical Bronze Spur Gears versus straight cut gears.

See through
screen shot2

 DFS780 Complete Vehicle Specific Fuel System

(Dodge Cummins 5.9L Boost Activated Kit Shown) Part No. 42-12032

Spur Gears
Installed Bracket_


A clear high-impact polycarbonate sight glass allows visual inspection of the fuel entering into the system.


The DFS780 uses a high efficiency fuel filter that connects to a clear water separation bowl. While the fuel filter is removing contaminants, the water separation bowl allows for visual inspection of the collected water and provides ease of draining using the removable cap.


The DFS780 is made specifically for each vehicle. It comes complete with all hardware, brackets, fuel lines and wire harnesses, allowing a simple installation. No cutting or drilling of the vehicle, and the installation is completely reversible.


 In addition to cleaning contaminants and removing air/vapor from the fuel, the DFS780 provides significant increases in both horsepower and torque.
42-12031 Component Shot

 DFS780 Complete Vehicle Specific Fuel System

(Dodge Cummins 5.9L Relay - Full time Kit Shown) Part No. 42-12031



1. Why do I need air separation?

Diesel fuel tends to “entrain” air due to its surface tension. Because of this, air can be trapped in the fuel and delivered to the high pressure pump where it gets compressed to 25,000+ psi. When these high pressure air bubbles are released through the fuel injector, they cause cavitation which is like small “explosions” that that eventually ruin the injectors.


2. How much HP do I need to use this pump? 

Though the DFS780 can be used on a totally stock diesel vehicle, it was engineered for modified vehicles. BSFC (Brake Specific Fuel Consumption) for most modern turbocharged diesel engines is about 0.36 lbs/HP/hr. Since #2 diesel weighs about 7 pounds/gallon, which gives us about 19.5 HP/gallon/hr. The DFS780 will flow enough fuel (at rated pressure) to support over 2000 HP. 


3. How many gallons per hour does the DFS780 flow?

aFe tests each DFS780 unit before it leaves our facility to ensure peak performance. Each pump has been flowed and rated at a minimum 2.0 gpm, which is capable of supporting over 2000 horsepower.


4. How many microns is the filter? 

The DFS780 fuel filter is rated at 5 microns @ 99% efficiency. Additionally, the DFS780 was designed to work in conjunction with your stock fuel filter, giving you the ability to have multi-step filtration.


5. What happens when I tow? Benefits?

When towing, you typically push the fuel system to its limits due to the continuous high loads. As the fuel requirements go up, the stock fuel system can’t always supply enough fuel, causing a loss in power. The DFS780 will provide more than enough fuel for almost all towing situations that there will be no loss of power.


6. What is the difference between the boost-operated and full-time system?

On some of our kits, we use a boost-activated switch to energize the DFS780 fuel pump. This allows the vehicle to run on the stock fuel pump during light load conditions and then when the power demands increase, the DFS780 pump “kicks in.” On the full-time system, the pump is active when the ignition is on.


7. What are Deutsch connectors?

Deutsch makes high quality weatherproof electrical connectors that are used in many O.E. (Original Equipment) applications, and why these are used with the DFS780, it’s the best.


8. I want to sell my truck. Can I put the fuel system back to stock?

The DFS780 was engineered for simple install and removal, allowing the vehicle to be easily returned to stock (unlike the competitors, we do not require you to drill/cut/modify the fuel tank).


9. Can I use this DFS on my stock truck?



10. I have some other mods like intake, exhaust, tuner and intercooler. Will this work on my truck?

Yes. The DFS780 is the perfect complement to other performance-enhancing modifications.


11. The other companies use 2 filters, why does DFS only have 1?

Other competitors use separate filter and water separator (not two filters). The DFS780 has integrated a clear water separation bowl onto the supplied high-efficiency fuel filter, eliminating the need (and expense) to replace two units. Additionally, the DFS780 was designed to work in conjunction with the factory fuel filter for even cleaner fuel.


12. How often do I need to change my fuel filter? Is the water separator bowl reusable?

Fuel filter change intervals will vary greatly depending on usage and fuel conditions. We have found 10k-20k miles replacements under normal conditions. And yes, the water separator bowl can be transferred from your old filter to your new aFe filter.


13. Will I feel the power?

The more modified the vehicle, the greater the power improvement. Most people report immediate “seat of the pants” drivability improvements.


14. Will I lose MPG?

As with most modifications, it varies. But the general feedback has been slightly improved fuel mileage.


15. Is the DFS continuously running?

Depending on the specific application, the DFS780 is either boost-activated or controlled with a relay system that turns the pump on while the engine is running.


16. How do I know the DFS780 is running?

Though the DFS780 does feature helical spur gears which are quieter than straight cut gears, you should be able to tell if the pump is running based upon feel.


17. How does the cost differ from other brands?

The DFS780 is priced higher than some competing units but they also lack some of our features and benefits. But, when you look at overall installed cost (with our reduced installation time), the DFS780 will typically come out as the best value.


18. Do I have choices of where I can install it?

Each DFS780 application is designed with specifically engineered mounting brackets (not generic). aFe will be offering a universal DFS780 kit for custom installations.






19. What is the warranty?

aFe’s obligation under the “Worry Free” Warranty is covered for two years from date of purchase. The “Worry Free” Warranty is limited to replacement of the defective or worn-out product with the same (or comparable) product in accordance with this warranty. Under no circumstances will the obligation or liability of aFe exceed the purchase price of the product as indicated on the original bill of sale. Warranties are non-transferable, contain no cash value and are only extended to the owner of the vehicle provided that the ownership has not changed since the installation of the product.


This warranty does not apply to products which have been altered, modified, damaged from neglect, abuse or from an accident, misused, improperly installed, contaminated with dirt or other contaminants, or used in applications other than recommended in our printed or digital media. aFe does not provide reimbursements for delay, shipping fees, labor, mileage, or any other costs involved in installation or re-installation of the products in question. 


Warranty Registration Process
Simply register your DFS Fuel System product online at
Claim Process
To file a warranty claim, customers are required to submit their information using the warranty claim form online at
All Warranty Claims require: 1) Online registration of the product.  2) If item has not been registered online, then a copy of your original purchase receipt is required. 3) An image of the warrantied part. 4) An image showing the serial number on the warranty card or the barcode label on the box. You may be required to return the part for inspection and you may be required to purchase a new replacement part while the warranty claim is being processed. Once the warranty claim has been reviewed and approved, aFe will provide you with a refund of the replacement purchase price.
aFe’s obligation under the “Worry Free” Warranty is limited to replacement of the defective or worn-out product (excluding finish) with the same (or comparable) product in accordance with this warranty. In addition this warranty does not cover fuel filters, which need to be replaced when worn. Warranty is valid provided aFe instructions for installation were properly followed.
This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
5 Easy Steps
1. File your claim
2. If you have not registered your product and you are the original owner, provide a copy of your original receipt and 

    Serial Number

3. Send aFe an image of the warrantied part
4. Once you receive an RGA #, Return the item. If you prefer not to send the item back before receiving a replacement, 

    aFe can send you a replacement part by authorizing your credit card. aFe must receive the warrantied item within 30 


5. aFe will pay the cost of 2nd day air (within continental United States) shipping of warrantied item.


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