The Merchant Automotive Fuel Rail Plug, also called a race valve, installs in place of the factory fuel pressure relief valve on the fuel rail of 2004.5–2010 LLY, LBZ and LMM 6.6L Duramax Silverado and Sierra 2500HD/3500HD trucks. The factory relief valve is designed to open and bleed off rail pressure, and on high-mileage or tuned trucks it can start opening too early, causing a loss of rail pressure and power. Our plug seals that port solid. Its end is machined with a flat sealing surface to address a common problem with over-tightening, which crushed the ledge in the rail and caused leaks. A new Viton O-ring is included.
Key Features
- Replaces the factory fuel rail pressure relief valve
- Flat-end design prevents ledge crushing from over-tightening
- Includes a Viton (FKM 75) O-ring
- Merchant Automotive branded
- Fits LLY, LBZ and LMM Duramax
Benefits
- Eliminates rail pressure loss from a relief valve that opens early
- Flat sealing surface helps prevent leaks at the rail
- Simple swap for the factory relief valve
Frequently Asked Questions
What does a race valve do?
It replaces the factory fuel pressure relief valve with a solid plug, so the relief valve can no longer open and bleed off rail pressure.
Why is the flat end important?
Earlier plug designs could crush the ledge inside the rail if they were over-tightened, which led to leaks. Our flat-end design addresses that problem.
Is an O-ring included?
Yes. A new Viton O-ring comes with the plug.
Would rather keep the factory relief valve?
See our Fuel Pressure Relief Valve Shim Kit and the Fuel Rail Relief Valve O-ring.
Fitment
- 2004.5–2010 Chevrolet Silverado 2500HD / 3500HD 6.6L Duramax (LLY, LBZ, LMM)
- 2004.5–2010 GMC Sierra 2500HD / 3500HD 6.6L Duramax (LLY, LBZ, LMM)
Working on the fuel system? See our Fuel Rail to Fuel Return Hose and Injection Pump Inlet Hose.
What's Included
- (1) Merchant Automotive fuel rail plug (race valve)
- (1) Viton O-ring
For warranty information or to submit a claim, see our Warranty Form.
