Description
12642623 Fuel Filter Head Kit + 1R-0750 CAT Filter Adapter — Duramax 6.6L
The 12642623 Fuel Filter Head Kit with 1R-0750 Refit Head is the ultimate fuel filtration upgrade for 2005-2016 GM Duramax 6.6L diesel trucks (LLY, LBZ, LMM, LML). This comprehensive package includes two components that address the biggest weaknesses of the factory fuel system:
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12642623 Billet Aluminum Filter Head — replaces the failure-prone plastic housing with a CNC-machined aluminum unit including an integrated hand primer pump and heater element
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1R-0750 Refit Adapter — converts your filter head to accept high-flow, lower-cost Caterpillar 1R-0750 spin-on filter elements (2-micron absolute filtration, $12-15 each)
Why the 1R-0750 conversion? The CAT 1R-0750 filter is widely regarded as the best spin-on fuel filter available — with 2-micron absolute filtration (vs. 4-micron for the standard TP3018), higher flow capacity, and availability at any heavy equipment dealer or truck stop across North America. This conversion has been a popular Duramax modification for over 15 years.
Key Features
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Billet Aluminum Filter Head: CNC-machined from solid 6061-T6 aluminum with electrophoresis coating — will never crack, warp, or leak like the OEM plastic housing
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1R-0750 CAT Filter Adapter: Precision-machined black anodized aluminum adapter that bolts to the 12642623 head — accepts standard CAT 1R-0750 filters
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Integrated Hand Primer Pump: Built-in iron-body primer pump for bleeding the system after filter changes
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Heater Element Included: Pre-installed fuel heater for cold-weather operation
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Upgraded Bleeder Screw: Aluminum bleeder screw replaces the OEM plastic screw
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Complete Hardware Kit: Includes mounting bolts, O-rings, and adapter hardware — everything needed for installation
Vehicle Compatibility
| Make |
Model |
Year |
Engine |
| Chevrolet |
Silverado 2500HD |
2005-2016 |
6.6L Duramax (LLY, LBZ, LMM, LML) |
| Chevrolet |
Silverado 3500HD |
2005-2016 |
6.6L Duramax (LLY, LBZ, LMM, LML) |
| GMC |
Sierra 2500HD |
2005-2016 |
6.6L Duramax (LLY, LBZ, LMM, LML) |
| GMC |
Sierra 3500HD |
2005-2016 |
6.6L Duramax (LLY, LBZ, LMM, LML) |
CAT 1R-0750 Filter Advantages
| Feature |
Standard TP3018 |
CAT 1R-0750 |
| Filtration Rating |
4 micron absolute |
2 micron absolute |
| Water Separation |
Standard |
Advanced AquaBlock media |
| Flow Rate |
Standard |
Higher — supports tuned engines |
| Availability |
Auto parts stores |
Any CAT dealer, truck stop, Amazon |
| Typical Price |
$25-35 |
$12-18 |
| Service Life |
15,000 miles |
15,000 miles |
FAQ
Q: Is this different from the standard 12642623 housing?
A: Yes — this kit includes the 12642623 billet filter head plus the 1R-0750 refit adapter. The standard 12642623 housing uses factory-style TP3018 filters. This kit converts to CAT 1R-0750 filters for 2-micron filtration and lower filter costs. Choose based on your filtration and budget priorities.
Q: Where do I buy CAT 1R-0750 replacement filters?
A: Any Caterpillar dealer, most heavy truck parts stores, NAPA (FIL 3960 crosses to 1R-0750), Amazon, and many online retailers. They're one of the most widely available filter elements in North America — and typically 30-50% cheaper than the TP3018.
Q: Will this fit my 2005 LLY?
A: Yes — compatible with 2005-2016 Duramax engines (LLY, LBZ, LMM, LML). If you have a 2001-2004 LB7, the filter housing mounting points are different — check fitment carefully.
Q: Is the 2-micron filtration too restrictive for a tuned engine?
A: No — the CAT 1R-0750 filter has a larger pleated surface area than the TP3018, so despite the tighter micron rating, it actually provides equal or better flow. This makes it ideal for tuned/towing trucks that demand maximum fuel delivery. Many 600+ hp Duramax builds use the 1R-0750 filter setup.
Q: Does this kit include a WIF sensor?
A: The filter head includes a pre-threaded WIF sensor port. Your existing water-in-fuel sensor transfers directly from the old housing. If your sensor is failing, we recommend replacing it during the swap.
Q: Can I switch back to TP3018 filters later?
A: Yes — the 1R-0750 adapter is removable. Simply unbolt it from the filter head and you're back to the standard M36 x 1.5 thread for TP3018 filters.
Q: Do I need to tune the ECU after installing this?
A: No tuning required. The filter head and adapter are purely mechanical components — they don't change fuel pressure, timing, or any ECM-managed parameters. It's a bolt-on hardware upgrade only.
Q: What's included in the 12642623 + 1R-0750 kit vs. just the filter head?
A: This kit includes two components: (1) The 12642623 billet aluminum filter head with integrated hand primer pump and fuel heater — replaces your factory plastic housing, and (2) The 1R-0750 Refit Adapter — a CNC-machined black anodized aluminum adapter that bolts to the filter head and converts the thread pattern to accept CAT 1R-0750 spin-on filters. If you only need the filter head (standard TP3018 thread), you can purchase the housing separately. The 1R-0750 adapter adds 2-micron absolute filtration capability and lets you use CAT filters available at any heavy equipment dealer nationwide.
Q: Why convert to CAT 1R-0750 filters?
A: The CAT 1R-0750 is widely considered the gold standard in spin-on diesel fuel filtration: 2-micron absolute rating (vs. 4-micron for standard TP3018), advanced AquaBlock water separation media, higher flow capacity for tuned/towing trucks, and nationwide availability at any Caterpillar dealer or truck stop. The conversion has been a popular Duramax modification for over 15 years — it's the same filter used on million-mile CAT heavy equipment engines. Once converted, replacement filters are widely available and the tighter filtration provides an extra margin of safety for your CP3 injection pump and fuel injectors.
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