Doc's Diesel Fuel Water Separator for 6.7L Cummins RAM 2500/3500 (2025–2026) — OE-fit, 3-micron water & particle protection

Doc's Diesel Fuel Water Separator DGF431 is a direct-fit replacement for RAM 6.7L Cummins 2500/3500/4500/5500 (2025–2026) that separates water and captures contaminants to protect your fuel system.

When you're maintaining a late-model RAM with the 6.7L Cummins, choosing the correct fuel/water separator matters for fuel system longevity and reliable performance. Doc's Diesel engineered the DGF431 assembly to match OE form and function while providing proven contaminant removal. Independent tests show the DGF430 and DGF401 family members achieve high particulate and water separation efficiency down to 3 microns, and this DGF431 unit ships as a complete service kit so you replace every matched component at once.

How does this separator protect my diesel engine on the road?

The separator removes free water and filters out dirt, rust, and other particulates before fuel reaches the high-pressure system. By keeping contaminants out of injectors and fuel pumps, it reduces wear and helps maintain consistent combustion and power delivery.

• Separates water from fuel to prevent corrosion in fuel components
• Captures particles down to 3 microns per independent testing of related Doc's components
• Reduces risk of clogged filters and injector damage

Will this unit fit my RAM 2500/3500/4500/5500 6.7L Cummins (2025–2026)?

Yes — the DGF431 is manufactured specifically for 6.7L Cummins engines in RAM 2500, 3500, 4500, and 5500 models for model years 2025–2026. Use the fitment card on the product page to verify your exact year and truck configuration before ordering to ensure a perfect match.

• Engine compatibility: 6.7L Cummins (diesel)
• Model years: 2025 and 2026 for RAM 2500/3500/4500/5500
• Confirm fit via the online fitment card prior to purchase

What comes in the box and how easy is installation?

The DGF431 kit ships as a matched assembly so you replace every required component during service, minimizing part mismatch and installation time. Installation follows standard fuel/water separator service procedures; some owners can complete the swap with basic tools, while others may prefer a professional service for torqueing and leak checks.

• Includes the DGF431 fuel/water separator assembly
• All parts matched to the application for a single-order service
• Fits OE mounting points — typical DIY swap for experienced owners

How often should I change this fuel/water separator?

Service intervals vary with driving conditions and manufacturer recommendations, but routine replacement preserves filtration efficiency. Doc's guidance and general best practice suggest changing the separator between 5,000 and 10,000 miles, with 15,000 miles as an upper limit before replacement.

• Recommended: every 5,000–10,000 miles for best protection
• Maximum interval: 15,000 miles unless manufacturer advises otherwise
• Shorten interval under harsh conditions: off-road, frequent short trips, or poor fuel quality

Who is this for: The DGF431 from Doc's Diesel is aimed at RAM owners with the 6.7L Cummins who want an exact-fit replacement that restores proper water separation and filtration. It's well suited to owner-mechanics who perform routine fuel-system service, fleet managers seeking reliable maintenance parts, and anyone who prefers a matched-component kit to reduce installation guesswork while protecting expensive fuel-system components.