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L5P|L5D Duramax Passenger Side Fuel Injection Fuel Rail – GM 12686808
Genuine GM / ACDelco OEM high-pressure fuel rail for the passenger (right) side of 2017–2023 Chevrolet Silverado and GMC Sierra 2500HD / 3500HD trucks equipped with the 6.6L L5P Duramax diesel, and 2019–2023 Chevrolet/GMC medium-duty trucks with the 6.6L L5D Duramax.
This is a factory original-equipment replacement rail that distributes high-pressure diesel from the injection pump to the four passenger-side injectors. It is a direct-fit assembly that typically includes the factory fuel rail pressure sensor.
Why replace the rail
The L5P/L5D common-rail system runs at very high pressure. Rails are commonly replaced after fuel contamination (water, debris, or metal from a failing high-pressure pump), leaks at the rail or sensor, a failed pressure sensor, or when the entire high-pressure circuit is being serviced. Using the genuine GM part restores correct rail pressure, injector feed, and sensor readings so the ECM can control fueling accurately.
Features & benefits
- Genuine GM OEM part — exact fit, mounting points, and function as the original rail
- Aluminum construction, factory gray finish
- Passenger-side (RH) high-pressure common-rail assembly
- Fuel rail pressure sensor included on most current assemblies
- Direct bolt-on replacement — no modification required
- Restores proper high-pressure fuel delivery, throttle response, cold starts, and fuel economy
- Designed, engineered, and validated to GM standards and backed by GM
What’s included
- Passenger-side fuel rail assembly (GM 12686808)
- Factory-installed fuel pressure sensor (commonly GM 12686809)
Fuel injectors, high-pressure lines, and seals/gaskets are not included.
Vehicle fitment
L5P Duramax (6.6L)
2017–2023
- Chevrolet Silverado 2500HD / 3500HD
- GMC Sierra 2500HD / 3500HD
L5D Duramax (6.6L)
2019–2023
- Chevrolet Silverado 4500HD / 5500HD / 6500HD
- Equivalent GMC medium-duty models
Confirm with VIN before ordering.
Replaces / supersedes: 12635938, 12678990
Specifications
- GM / ACDelco part number: 12686808
- Position: Passenger side (right / RH)
- Material: Aluminum
- Color: Gray
- Approximate length: 18.75 in
- Fuel injectors included: No
- Fuel system: High-pressure common rail (diesel)
Installation notes
Professional installation is strongly recommended. High-pressure diesel fuel systems require proper bleeding, torque specs, and cleanliness. After installation, check for leaks and verify fuel rail pressure with a scan tool. Always confirm fitment with your VIN.
L5P|L5D Duramax Passenger Side Fuel Injection Fuel Rail – GM 12686808
Genuine GM / ACDelco OEM high-pressure fuel rail for the passenger (right) side of 2017–2023 Chevrolet Silverado and GMC Sierra 2500HD / 3500HD trucks equipped with the 6.6L L5P Duramax diesel, and 2019–2023 Chevrolet/GMC medium-duty trucks with the 6.6L L5D Duramax.
This is a factory original-equipment replacement rail that distributes high-pressure diesel from the injection pump to the four passenger-side injectors. It is a direct-fit assembly that typically includes the factory fuel rail pressure sensor.
Why replace the rail
The L5P/L5D common-rail system runs at very high pressure. Rails are commonly replaced after fuel contamination (water, debris, or metal from a failing high-pressure pump), leaks at the rail or sensor, a failed pressure sensor, or when the entire high-pressure circuit is being serviced. Using the genuine GM part restores correct rail pressure, injector feed, and sensor readings so the ECM can control fueling accurately.
Features & benefits
Genuine GM OEM part — exact fit, mounting points, and function as the original rail
[...]
L5P|L5D Duramax Passenger Side Fuel Injection Fuel Rail – GM 12686808
Genuine GM / ACDelco OEM high-pressure fuel rail for the passenger (right) side of 2017–2023 Chevrolet Silverado and GMC Sierra 2500HD / 3500HD trucks equipped with the 6.6L L5P Duramax diesel, and 2019–2023 Chevrolet/GMC medium-duty trucks with the 6.6L L5D Duramax.
This is a factory original-equipment replacement rail that distributes high-pressure diesel from the injection pump to the four passenger-side injectors. It is a direct-fit assembly that typically includes the factory fuel rail pressure sensor.
Why replace the rail
The L5P/L5D common-rail system runs at very high pressure. Rails are commonly replaced after fuel contamination (water, debris, or metal from a failing high-pressure pump), leaks at the rail or sensor, a failed pressure sensor, or when the entire high-pressure circuit is being serviced. Using the genuine GM part restores correct rail pressure, injector feed, and sensor readings so the ECM can control fueling accurately.
Features & benefits
- Genuine GM OEM part — exact fit, mounting points, and function as the original rail
- Aluminum construction, factory gray finish
- Passenger-side (RH) high-pressure common-rail assembly
- Fuel rail pressure sensor included on most current assemblies
- Direct bolt-on replacement — no modification required
- Restores proper high-pressure fuel delivery, throttle response, cold starts, and fuel economy
- Designed, engineered, and validated to GM standards and backed by GM
What’s included
- Passenger-side fuel rail assembly (GM 12686808)
- Factory-installed fuel pressure sensor (commonly GM 12686809)
Fuel injectors, high-pressure lines, and seals/gaskets are not included.
Vehicle fitment
L5P Duramax (6.6L)
2017–2023
- Chevrolet Silverado 2500HD / 3500HD
- GMC Sierra 2500HD / 3500HD
L5D Duramax (6.6L)
2019–2023
- Chevrolet Silverado 4500HD / 5500HD / 6500HD
- Equivalent GMC medium-duty models
Confirm with VIN before ordering.
Replaces / supersedes: 12635938, 12678990
Specifications
- GM / ACDelco part number: 12686808
- Position: Passenger side (right / RH)
- Material: Aluminum
- Color: Gray
- Approximate length: 18.75 in
- Fuel injectors included: No
- Fuel system: High-pressure common rail (diesel)
Installation notes
Professional installation is strongly recommended. High-pressure diesel fuel systems require proper bleeding, torque specs, and cleanliness. After installation, check for leaks and verify fuel rail pressure with a scan tool. Always confirm fitment with your VIN.