Description
Fix Your Duramax Fuel Filter Head for $13.99 — Instead of $200+ for a New Housing
If your Duramax is leaking fuel from the filter housing, the hand primer feels mushy, or the truck stalls shortly after startup, you don't need a $200+ replacement filter head. In most cases, the seals have simply hardened and the plastic bleeder screw has failed — both of which are fixed with this 6-piece rebuild kit + aluminum bleeder screw upgrade for less than fourteen bucks.
What's in the Kit
| Part |
Material |
What It Fixes |
| Aluminum Bleeder Screw ×1 |
Billet 6061-T6 Aluminum, Black Anodized |
Replaces fragile plastic bleeder that strips & cracks |
| Plunger U-Cups ×2 |
Nitrile Rubber |
Restores primer pump pressure — no more "mushy" feel |
| Viton O-Rings ×4 |
Viton (Fluorocarbon) |
Seals fuel & air pathways, stops leaks at the housing |
🚛 Vehicle Compatibility
Fits all 2001–2013 GM 6.6L Duramax fuel filter housings across these platforms:
- Chevrolet Silverado 2500HD/3500HD (2001–2013)
- GMC Sierra 2500HD/3500HD (2001–2013)
- Chevrolet Kodiak / GMC TopKick C4500–C8500
- Engine codes: LB7 (2001–2004), LLY (2004.5–2005), LBZ (2006–2007), LMM (2007.5–2013)
When You Need This Kit
🔧 Fuel Leak at the Filter Head — Fuel pooling near the bleeder screw or around the primer pump means the O-rings have hardened. This kit replaces all serviceable seals in one shot.
🔧 Soft or Non-Functional Hand Primer — If the primer won't build pressure after 10–15 pumps, the plunger U-cups are worn. These nitrile seals restore the vacuum needed to pull fuel from the tank.
🔧 Bleeder Screw Stripped or Cracked — The stock GM plastic bleeder screw is notorious for stripping threads and cracking. Our CNC-machined 6061-T6 aluminum bleeder is a lifetime upgrade — it won't strip, crack, or leave fragments inside the housing.
🛠️ Installation Tips
-
Relieve fuel pressure before disconnecting any lines — loosen the bleeder screw first.
- Use a small pick tool to remove old O-rings without scratching sealing surfaces.
-
Lubricate all seals with clean engine oil before installation to prevent pinching.
- The orange O-ring goes on the bleeder screw — don't mix it up with the Viton housing O-rings.
- The plunger U-cups install with the lip facing away from the flange for the outer seal, and toward the flange for the inner seal.
- After reassembly, test the primer before reinstalling on the truck — place your thumb over the inlet and pump until you feel vacuum.
❓ Frequently Asked Questions
Q: Will this kit fit my LML (2011–2016) Duramax?
This kit is designed for 2001–2013 filter heads (LB7 through LMM). The LML (2011–2016) uses a different filter housing design. For LML applications, check our Duramax collection for the correct kit.
Q: Do I need to remove the entire filter head from the truck?
Yes — the plunger U-cups and O-rings are installed inside the filter head housing, which requires the assembly to be on a workbench. The job takes about 45–60 minutes start to finish. Our step-by-step Duramax filter head rebuild guide walks you through every step.
Q: The molded rubber seals inside my primer housing are leaking — does this kit include them?
No — the molded seals inside the primer housing are not serviceable. If those have failed, you need a complete filter head replacement (ACDelco 12642623 or Dorman 904-401). Our rebuild kit addresses the 6 serviceable seals that cause 90%+ of filter head issues.
Q: How is this aluminum bleeder screw better than the stock plastic one?
The stock plastic bleeder screw strips threads easily, cracks from heat cycling, and can leave plastic fragments inside the fuel housing. Our billet 6061-T6 aluminum screw is CNC-machined, black anodized for corrosion resistance, and uses the same thread pitch as OEM — it's a direct drop-in replacement that will outlast the truck.
Q: Do I need a new fuel filter after rebuilding the filter head?
Yes. Once the filter head is opened to air, contaminants can enter. Install a fresh fuel filter (ACDelco TP3018 or equivalent) and prime the system fully before starting the engine. Browse our diesel fuel filter collection for compatible filters.
