Product Description
The CUMMINS 3900808 OEM 9MM FUEL INJECTOR SEALING WASHER is designed for 1989–1991 Dodge Ram trucks equipped with the 5.9L Cummins diesel engine. This genuine Cummins sealing washer helps create a proper seal between the fuel injector and cylinder head to maintain correct combustion chamber sealing and injector performance.
Use this part when replacing fuel injectors, servicing the fuel system, repairing injector leaks, or rebuilding a 5.9L Cummins engine. Always replace injector sealing washers during injector installation to help ensure proper sealing and long-term reliability.
FEATURES
- Genuine Cummins OEM fuel injector sealing washer
- 9mm injector sealing washer design
- Direct-fit replacement for factory applications
- Helps maintain proper injector sealing and combustion efficiency
- Recommended during injector replacement and engine service
- Built to Cummins OEM specifications
FITMENT
- 1989–1991 Dodge Ram 2500 5.9L Cummins
- 1989–1991 Dodge Ram 3500 5.9L Cummins
- 5.9L Cummins 12-Valve diesel engines
WHAT'S INCLUDED
- 1 Cummins 3900808 OEM 9mm Fuel Injector Sealing Washer
CROSS-REFERENCE AND RELATED PRODUCTS
- Cummins 3900808
- Fuel Injector Hold-Down Hardware
- Fuel Injector Return Line Components
- 5.9L Cummins Fuel Injectors
SPECIFICATIONS
- Manufacturer: Cummins
- Part Number: 3900808
- Part Type: Fuel Injector Sealing Washer
- Washer Size: 9mm
- Engine Compatibility: 5.9L Cummins 12-Valve
- Fitment Years: 1989–1991
- Vehicle Application: Dodge Ram 2500 / 3500
- Condition: New OEM Cummins
- Installation Location: Fuel Injector to Cylinder Head
- Installation Type: Direct Replacement
FAQ
Will this sealing washer fit my truck?
This washer fits many 1989–1991 Dodge Ram trucks equipped with the 5.9L Cummins diesel engine. Always verify fitment before ordering.
Is this a genuine Cummins part?
Yes. Cummins 3900808 is a genuine OEM Cummins fuel injector sealing washer.
Why should injector sealing washers be replaced?
Injector sealing washers compress during installation and should be replaced whenever injectors are removed to help maintain proper combustion chamber sealing.
What happens if an injector sealing washer leaks?
A failed sealing washer can contribute to combustion leakage, reduced performance, difficult starting, and potential cylinder head contamination.
How many sealing washers are required?
The required quantity depends on the number of injectors being serviced. One washer is required per injector.
Do I need any related parts?
Inspect injector hold-down hardware, return line seals, injector bodies, and fuel system components during installation and replace worn parts as necessary.
