For 6.7L Cummins owners, the factory lift pump is often the first component to be upgraded. A robust aftermarket fuel pump is not just about preventing a costly failure on the side of the road; it’s about ensuring your high-pressure fuel injection system receives a consistent, clean supply of diesel. Contaminants like air, water, and debris are the primary enemies of your CP3 or CP4 injection pump, and a quality lift pump is your first line of defense.
Whether you’re running a stock truck, towing heavy loads, or pushing higher horsepower levels, there is a fuel system designed for your needs. Upgrading can lead to improved fuel economy, better cold-weather starting, and the peace of mind that comes with protecting your significant investment. This roundup covers eight of the best aftermarket fuel pumps available, from trusted names like FASS and AirDog to reliable OEM-style replacements, to help you make an informed decision for your diesel.
Our Top Picks for 6.7 Cummins Fuel Pumps
- FASS Titanium Signature Series 165GPH Diesel Fuel System
- FASS Titanium Signature Series Diesel Fuel Lift Pump 100GPH
- Flynsu 165 GPH Fuel Lift Pump Replacement for 2005-2018
- FASS Titanium Signature Series Diesel Fuel Lift Pump 250GPH
- FASS Titanium Signature Series Diesel Fuel Lift Pump 290GPH
- FASS Titanium Series 165-GPH Fuel System for 6.7L
- AirDog II DF-165 100-psi 6.7L Cummins Lift Pump
- S&B Filters 75-5067B Fuel Pump Assembly for 6.7L
FASS Titanium Signature Series 165GPH Diesel Fuel System
The FASS Titanium Signature Series 165GPH system is a popular choice for 6.7L Cummins owners seeking a balance of performance and protection. It is engineered to safeguard your expensive fuel injection system by providing clean, air-free fuel. This directly contributes to maintaining optimal injector performance and can help avoid premature wear and costly repairs.
This model is designed to optimize fuel mileage under various driving conditions and improves cold-weather performance, ensuring a more reliable start when temperatures drop. With a flow rate of 165 gallons per hour, it is well-suited for stock to moderately tuned trucks, making it a versatile upgrade for daily drivers and work trucks alike.
FASS Titanium Signature Series Diesel Fuel Lift Pump 100GPH
For those with a stock or lightly used 6.7L Cummins, the FASS 100GPH model offers essential protection without overkill. It provides the same core filtration and air-separation technology as its higher-flow siblings, ensuring your injection system is shielded from harmful contaminants. This makes it a cost-effective insurance policy for your engine’s fuel system.
The primary benefit of this unit is its focus on extending the life of your injection system. By removing air and particulates from the fuel, it promotes smoother engine operation and can contribute to better fuel economy. Its 100 GPH flow rate is perfectly adequate for factory horsepower levels, providing reliable performance for everyday driving.
Flynsu 165 GPH Fuel Lift Pump Replacement
The Flynsu 165 GPH pump serves as a direct replacement for the FASS TSD07165G model, offering a more budget-friendly alternative. It is designed to fit 2005-2018 Dodge Ram trucks with the 5.9L or 6.7L Cummins engine, providing a straightforward solution for a failing OEM pump or for those looking for an upgrade on a tighter budget.
This pump delivers a solid 165 gallons per hour flow rate, which is sufficient for most applications. As a direct-fit component, installation is generally uncomplicated for those familiar with basic mechanical work. It represents a practical choice for restoring fuel system performance and reliability without a significant financial outlay.
FASS Titanium Signature Series Diesel Fuel Lift Pump 250GPH
Stepping up in performance, the FASS 250GPH system is built for 6.7L Cummins engines that are tuned or used for heavy towing. The increased flow rate ensures that your high-pressure fuel pump never starves for fuel, even under high demand. This is critical for maintaining engine power and health when you need it most.
This model includes all the signature FASS benefits, including exceptional protection for your injection system and the potential for optimized fuel mileage. A key feature is its advanced ability to remove water, air, and debris from diesel fuel, providing a higher level of filtration that is especially valuable when fuel quality may vary.
FASS Titanium Signature Series Diesel Fuel Lift Pump 290GPH
The FASS 290GPH represents the high end of the Signature Series, engineered for high-performance applications. With a flow rate capable of supporting engines up to 1,500 horsepower, this pump is for serious enthusiasts and competitors who have significantly modified their 6.7L Cummins.
Beyond its immense flow capacity, this system is a guardian for your fuel system. It is specifically designed to protect and extend the life of your injection system by aggressively removing water, air, and debris. For those building a powerful truck, this fuel pump provides the foundation for reliable, high-horsepower operation.
FASS Titanium Series 165-GPH Fuel System for 6.7L Cummins
Another robust option from FASS, the Titanium Series 165-GPH system, is a complete fuel system upgrade. It is built to deliver clean, air-free fuel consistently, which is the cornerstone of injection system longevity and engine performance. This system is ideal for owners who want the reliability of the FASS brand with a focus on comprehensive fuel management.
By ensuring a pure fuel supply, this pump helps maintain peak combustion efficiency. This can lead to smoother idle, better throttle response, and consistent power delivery. It’s a solid investment for any 6.7L Cummins owner looking to enhance their truck’s reliability and performance for the long term.
AirDog II DF-165 100-psi 6.7L Cummins Lift Pump System
AirDog is a respected name in diesel fuel systems, and the AirDog II DF-165 is a direct competitor designed for the 6.7L Cummins. This system is known for its four-stage filtration process, which excels at removing damaging air bubbles from the fuel. This process of air separation is vital for preventing cavitation and wear in the high-pressure injection pump.
Operating at 100 psi, this lift pump provides ample pressure and a 165 GPH flow rate to support a wide range of applications. Its design focuses on maximum filtration and air removal, making it an excellent choice for owners who prioritize ultimate fuel cleanliness and the protection of their entire fuel system.
S&B Filters 75-5067B Fuel Pump Assembly for 6.7L Cummins
For those seeking a more direct, OEM-style replacement, the S&B Filters Fuel Pump Assembly is a premium option. It is designed as a complete drop-in unit that replaces the entire factory assembly, offering a simple and clean installation process. This makes it a great choice for owners who want improved reliability without a complex aftermarket setup.
S&B is known for its high-quality filtration products, and this pump assembly continues that tradition. It provides a reliable fuel supply and is an excellent solution for restoring a truck to its original operating condition with a component known for its quality and durability. It’s the perfect plug-and-play upgrade for a stock vehicle.
Buying Guide: How to Choose the Best Aftermarket Fuel Pump for Your 6.7 Cummins
When my stock CP3 started showing its age, I knew I needed to start looking at the best aftermarket fuel pumps for the 6.7 Cummins. It’s not a decision to take lightly, as the fuel pump is the literal heart of your engine’s performance. Getting it wrong can mean poor performance or, even worse, a catastrophic failure that takes out your entire fuel system. So, let’s talk about what I think you should focus on when making your choice.
First, you need to be honest about your truck’s setup and your future goals. Are you running a mostly stock truck and just want a reliable replacement? Or are you planning on adding a tuner and bigger injectors down the line? For a stock or lightly modified truck, a high-quality direct replacement CP3 is often the best bet. It bolts right in and offers improved reliability over the stock unit. If you’re chasing big power, a dual CP3 kit or a high-flow single pump like a CP4 conversion kit is the way to go. These setups provide the immense fuel volume needed to support serious horsepower.
Next, consider the quality of the components. Not all aftermarket pumps are created equal. I always look for pumps that use high-strength internals, like hardened rollers and plungers. The materials and manufacturing tolerances are what separate a pump that lasts 50,000 miles from one that lasts 200,000. Reputation matters a ton here. Stick with brands that have a proven track record in the diesel performance world. A cheap, no-name pump might save you a few bucks upfront, but it’s a gamble I’m not willing to take with my engine.
Finally, think about the installation process and what else you might need. A simple pump swap might be something you can handle in your garage with some basic tools. However, a dual pump setup or a CP4 to CP3 conversion is a much more involved job that often requires custom lines, a lift pump upgrade, and potentially a tune adjustment. Make sure you factor in the cost and availability of any additional parts. Also, check the warranty. A company that stands behind its product with a solid warranty gives me a lot more confidence in my purchase. Taking the time to match the pump to your specific needs is the key to a happy and powerful truck.
Frequently Asked Questions
Why should I consider replacing my 6.7 Cummins fuel pump with an aftermarket one?
The main reason is reliability and performance. The stock CP3 on earlier models is generally robust, but it can still wear out over time. For later models that came with a CP4 pump, the reason is even more critical. The CP4 is known for its susceptibility to failure, especially with today’s lubricity standards in diesel fuel. When a CP4 fails, it often sends metal shards throughout the entire fuel system, which is an incredibly expensive fix. An aftermarket CP3 conversion kit is a popular preemptive upgrade to avoid that disaster. Beyond reliability, aftermarket pumps can support more fuel flow, which is necessary if you’re adding power with tuners or larger injectors.
What is the difference between a single and dual fuel pump setup?
A single pump setup is just that: one primary high-pressure fuel pump. This is fine for most applications, from stock trucks to those with moderate performance upgrades. A dual pump setup uses two CP3 pumps working in tandem. This is for extreme high-horsepower builds. The dual setup effectively doubles the potential fuel volume available to the engine, which is necessary when you’re pushing the limits of big injectors and high boost. For the vast majority of us, a single, high-flow aftermarket pump is more than sufficient. You only need to step up to a dual setup if you’re building a dedicated race truck or a tow rig with extreme power goals.
Do I need to upgrade my lift pump if I install a new high-pressure pump?
In my opinion, it’s a very good idea. Your lift pump (or in-tank pump) is what feeds fuel to the high-pressure pump. If your lift pump can’t supply a consistent volume of fuel at adequate pressure, you can starve the high-pressure pump. This can lead to premature wear and even failure. When you install a more demanding aftermarket high-pressure pump, ensuring it has a healthy supply of fuel is critical. Upgrading to a higher-flow lift pump is a relatively inexpensive insurance policy that protects your significant investment in one of the best aftermarket fuel pumps for the 6.7 Cummins.
Can I install an aftermarket fuel pump myself?
This depends entirely on your mechanical skill level and the specific pump kit you buy. Swapping a stock CP3 for another direct-replacement CP3 is a job that a competent DIYer can often handle with basic tools and a service manual. However, jobs like a CP4 to CP3 conversion or installing a dual pump kit are much more complex. They involve removing multiple components, running new fuel lines, and potentially dealing with custom mounting brackets. If you’re not comfortable with tasks that require precise torque specs and dealing with high-pressure fuel lines, it’s best to leave this job to a qualified diesel performance shop.
Will an aftermarket fuel pump improve my fuel economy?
Not directly, no. The primary job of the fuel pump is to supply fuel at the pressure and volume demanded by the engine’s computer. A new pump won’t change your air-to-fuel ratios or ignition timing on its own. However, if your old pump was worn out and not delivering fuel efficiently, a new pump could restore lost performance and potentially bring your fuel economy back to its original spec. Any real gains in fuel economy typically come from supporting modifications and, most importantly, your driving habits.