Product Description
Wehrli WCF100023 LB7 Fuel Pressure Relief Valve Delete Kit
The WEHRLI WCF100023 2001-2004 LB7 Duramax Fuel Pressure Relief Valve Delete Kit is designed to remove the factory High Pressure Fuel Relief Valve (FPRV) located on top of the intake runner. This frees up critical clearance in the engine valley so you can run larger aftermarket Y-bridges or turbo inlet horns that would otherwise interfere with the factory hard lines and valve body.
This kit is the same style FPRV block-off used in WCFab LB7 Y-bridge and intake bundle kits, giving you a clean, reliable way to re-route return fuel while deleting the bulky OE relief assembly.
Key Features & Benefits
- Deletes the factory Fuel Pressure Relief Valve (FPRV) on LB7 fuel rails.
- Provides additional clearance for larger Y-bridges and turbo inlet / intake horn upgrades.
- Simple, clean return-line routing with included 5/16" hose and brass tee.
- Stainless block-off plug for long-term durability in high-pressure, high-heat environments.
- Compatible with stock and aftermarket high-pressure fuel system components.
- Ideal companion to WCFab LB7 Y-bridge and Stage 1 High Flow Intake Bundle kits.
What's Included
- Stainless steel fuel rail block-off plug (replaces factory FPRV on LB7 rail).
- 5/16" fuel hose for return-line re-routing.
- 5/16" brass tee fitting for integrating into the return circuit.
- Hose clamps for secure, leak-free connections.
Vehicle Fitment
This kit is built specifically for the LB7 platform:
- 2001-2004 Chevrolet Silverado 2500HD / 3500HD 6.6L Duramax LB7
- 2001-2004 GMC Sierra 2500HD / 3500HD 6.6L Duramax LB7
Fits trucks retaining the factory-style common-rail fuel system. Intended for setups using high-flow Y-bridges, compound turbo kits, or upgraded turbo inlet horns that need extra clearance in the intake runner area.
Installation & Usage Notes
- The stainless block-off plug installs in place of the factory Fuel Pressure Relief Valve on the LB7 fuel rail.
- Supplied 5/16" hose and brass tee fitting allow you to re-route the small return line around the deleted FPRV body for a clean, low-profile install.
- These parts are standard equipment in WCFab LB7 Y-bridge kits; this standalone kit is ideal if you are piecing your setup together or replacing worn components.
- Professional installation is recommended. Always verify for leaks and proper rail-pressure control after any fuel system modification.
Recommended Wehrli Upgrades & Related CPP Diesel Products
Pair the WCF100023 Fuel Pressure Relief Valve Delete Kit with these Wehrli upgrades to build a complete, high-flow LB7 intake and charge-air system:
- WEHRLI WCF100411 2001-2004 LB7 DURAMAX STAGE 1 HIGH FLOW INTAKE BUNDLE KIT – includes a 3" Y-bridge and intercooler pipes for a full high-flow intake tract.
- WEHRLI WCF100693 2001-2004 LB7 DURAMAX Y-BRIDGE KIT – high-flow 3" Y-bridge kit for LB7 that often requires FPRV delete clearance.
- WEHRLI WCF100570 2001-2004 LB7 DURAMAX S400/STOCK TWIN (COMPOUND) TURBO KIT – compound turbo setup that benefits from all available intake and fuel-system clearance.
Specifications
| Specification | Details |
|---|---|
| Brand | Wehrli Custom Fab (WCFab) |
| Manufacturer Part Number | WCF100023 |
| CPP Diesel SKU | WCF100023 |
| Engine Compatibility | 6.6L Duramax LB7 (common-rail) |
| Model Years | 2001-2004 GM 2500HD / 3500HD trucks |
| Primary Application | Fuel Pressure Relief Valve (FPRV) block-off / delete kit |
| Included Components | Stainless block-off plug, 5/16" fuel hose, 5/16" brass tee fitting, hose clamps |
| Hose Size | 5/16" fuel return line |
| Construction | Stainless plug, brass tee, fuel-rated hose and clamps |
| Typical Uses | Clearing room for high-flow Y-bridges, turbo inlet horns, and compound turbo kits |
| Shipping Weight (approx.) | 2.0 lb |
| Package Dimensions (approx.) | 9.0 in (L) x 1.0 in (H) x 11.0 in (W) |
| Emissions Note | Intended for off-road / competition use in some regions. Always check and comply with local laws. |
| Prop 65 Warning (California) | WARNING: Cancer and Reproductive Harm – www.P65Warnings.ca.gov |
FAQ
Does this kit increase my LB7's fuel rail pressure?No. This kit removes and blocks off the factory Fuel Pressure Relief Valve to gain clearance and clean up plumbing. Actual commanded rail pressure is controlled by your truck's ECM, tuners, and the high-pressure fuel system components, not by this block-off plug.
Do I need this kit if I'm installing a WCFab LB7 Y-bridge or intake bundle?
Many WCFab LB7 Y-bridge and Stage 1 High Flow Intake Bundle kits already include an FPRV block-off solution. If you purchased a used kit, are piecing parts together, or want a fresh set of components, this WCF100023 kit is the correct standalone FPRV delete to use.
Is tuning required after installing the FPRV delete kit?
In most cases, this kit does not require specific tuning changes by itself, since it functions as a block-off and line re-route. However, any time you are modifying fuel-system components, work with a qualified tuner or technician to verify safe rail-pressure targets and overall engine health.
Will this kit cause fuel leaks or check-engine lights?
When installed correctly with good hose cuts, secure clamps, and clean sealing surfaces, the kit is designed to be leak-free and trouble-free. Always double-check for leaks after installation and scan for any stored diagnostic trouble codes after road testing.
Is this product legal for on-road use everywhere?
Regulations vary by state and country. Because this kit modifies factory fuel-system hardware, it may be limited to off-road or competition use only in some areas. Always verify and follow local emissions and safety laws before installing on a street-driven vehicle.
