FASS Drop-In Series Diesel Fuel System (2003-2024 5.9/6.7L Cummins)

FASS Drop-In Series Fuel System – For 2003 to 2024 Dodge/RAM Cummins 5.9L / 6.7L

Please Note: THIS IS NOT A LIFT PUMP! This is an air separation/filtration system that utilizes your factory lift pump.

Fits: 2003-2007 RAM 2500 & RAM 3500 5.9L Cummins (WITH AN IN-TANK LIFT PUMP). 2003-2004.5 trucks MUST have been retrofitted with an in-tank lift pump in order to utilize this product.

Please Note: Installation of this kit on a cab and chassis may require modifications. Drop-In Fuel Systems are a plug-and-play filtration upgrade and are not compatible with our Fuel Sump Kit. No additional items are needed for installation. This plug-and-play filtration system retains the Cummins OEM in-tank fuel pump.

The FASS Drop-In Series Diesel Fuel System was engineered by FASS to be the most effective filtration solution for the 5.9L and 6.7L Cummins. Backed by our limited lifetime warranty, the Drop-In Series Fuel System protects your 5.9L or 6.7L Cummins from the issues caused by fuel contamination.

If you drive a Ram with a Cummins diesel engine and want better fuel filtration, improved reliability, and injector protection without adding an external frame-mounted pump, the FASS Drop-In Series Fuel System is the perfect solution.

Designed as a direct replacement for the factory engine fuel filter, the Drop-In Series delivers cleaner fuel, better water separation, and consistent fuel supply while retaining a factory-style installation.

Reliability, Simplicity, Protection

• Supports Stock & Modified Cummins: Plenty of fuel for stock and modified Rams.
• Injector Protection: Will triple the life of your injectors and injection pump.
• FASS Filtration: Optimizes combustion, restores HP, maximizing MPG (results vary).
• Limited Lifetime Warranty: Register your FASS system, and you’re covered.

Advanced Filtration Technology

• Water Separation: 3rd-party proven to eliminate over 99% of water.
• Air/Vapor Removal: Eliminates entrained air and vapor that damages injection systems and reduces power/efficiency.
• 2 Micron Absolute Filtration - Microglass: Removes debris smaller than OEM filters can catch.

Key Benefits

• Improves Reliability: Triples the injection system life
• Maximized Horsepower: Improved fuel atomization, restored injection timing
• Optimized MPG: More efficient/complete combustion (results may vary)
• Peace of Mind: The Extreme Water Separator acts as a fail‑safe
• Extreme Cold Weather Confidence: Dependable starts and operation in extreme cold weather
• Cleaner Operation: Reduces DPF regens and soot output
• Improves fuel lubricity at least 10%

Key Features

• The only drop‑in 5.9L and 6.7L filtration system that retains functionality of the OEM water‑in‑fuel light via WIF sensor.
• The only drop‑in 6.7L Cummins filtration system with air separation!
• 100% drop‑in, no additional modifications needed.
• Retains the factory in‑tank lift pump.
• Performance Radius Cuts (PRC): Smoother internal fuel flow.
• 2‑micron absolute filtration rating: Captures finer debris than OEM filters.
• Removes over 99% of water (3rd‑party verified).
• Patented FASS air/vapor removal process.
• Bypasses OEM engine‑mounted filter and rear‑mounted filter (if equipped) reducing maintenance cost.
• Supplied with 3/8” fuel line to replace OEM feed line from tank to CP3.
• Heater options available for cold weather reliability.
• Limited Lifetime Warranty (with registration).

Why Choose FASS?

At FASS, we design fuel systems with longevity, reliability, and real‑world use in mind. The Drop‑In Series is engineered for diesel owners who want proven filtration technology and injector protection—without changing the character of their truck.

Vehicle Fitment by Year

• 2003 Dodge Ram 2500/3500 – 5.9L Cummins
• 2004 Dodge Ram 2500/3500 – 5.9L Cummins
• 2005 Dodge Ram 2500/3500 – 5.9L Cummins
• 2006 Dodge Ram 2500/3500 – 5.9L Cummins
• 2007 Dodge Ram 2500/3500 – 5.9L Cummins
• 2007.5 Dodge Ram 2500/3500 – 6.7L Cummins
• 2008 Dodge Ram 2500/3500 – 6.7L Cummins
• 2009 Dodge Ram 2500/3500 – 6.7L Cummins
• 2010 RAM 2500/3500 – 6.7L Cummins
• 2011 RAM 2500/3500 – 6.7L Cummins
• 2012 RAM 2500/3500 – 6.7L Cummins
• 2013 RAM 2500/3500 – 6.7L Cummins
• 2014 RAM 2500/3500 – 6.7L Cummins
• 2015 RAM 2500/3500 – 6.7L Cummins
• 2016 RAM 2500/3500 – 6.7L Cummins
• 2017 RAM 2500/3500 – 6.7L Cummins
• 2018 RAM 2500/3500 – 6.7L Cummins
• 2019 RAM 2500/3500 – 6.7L Cummins
• 2020 RAM 2500/3500 – 6.7L Cummins
• 2021 RAM 2500/3500 – 6.7L Cummins
• 2022 RAM 2500/3500 – 6.7L Cummins
• 2023 RAM 2500/3500 – 6.7L Cummins
• 2024 RAM 2500/3500 – 6.7L Cummins