Product Description
The CUMMINS 3904105 OEM EXHAUST VALVE SEAT (VALVE INSERT) is designed for 1989–1998 5.9L 12-valve Cummins diesel engines. This genuine Cummins cylinder head component provides a precision-machined sealing surface for the exhaust valve while maintaining OEM fitment, durability, and combustion chamber integrity.
Use this part when rebuilding a cylinder head, repairing valve seat damage, or restoring proper valve sealing after wear or machine work. Always verify fitment by engine serial number and part number before ordering.
FEATURES
- Genuine Cummins OEM exhaust valve seat insert
- Precision-machined for proper valve sealing
- Direct replacement for worn or damaged valve seats
- Designed for cylinder head rebuilding and repair
- Maintains proper compression and combustion efficiency
- Manufactured to Cummins OEM specifications
FITMENT
- 1989–1998 Dodge Ram 2500 5.9L Cummins 12-Valve
- 1989–1998 Dodge Ram 3500 5.9L Cummins 12-Valve
- 1989–1998 Cummins 6BT 5.9L diesel engines
- Select industrial and commercial 6BT applications
WHAT'S INCLUDED
- 1 Cummins 3904105 OEM Exhaust Valve Seat (Valve Insert)
CROSS-REFERENCE AND RELATED PRODUCTS
- Cummins 3904105
- Exhaust Valves
- Intake Valves
- Valve Guides
- Cylinder Head Gasket Sets
SPECIFICATIONS
- Manufacturer: Cummins
- Part Number: 3904105
- Part Type: Exhaust Valve Seat / Valve Insert
- Engine Compatibility: 5.9L Cummins 12-Valve (6BT)
- Fitment Years: 1989–1998
- Vehicle Application: Dodge Ram 2500 / 3500
- Cylinder Head Component: Yes
- Condition: New OEM Cummins
- Installation Type: Machine-Shop Installation Recommended
FAQ
Will this part fit my engine?
This exhaust valve seat is designed for 1989–1998 5.9L 12-valve Cummins engines. Always verify fitment using your engine serial number before ordering.
What is an exhaust valve seat?
The exhaust valve seat provides the hardened sealing surface between the exhaust valve and cylinder head, helping maintain compression and proper combustion chamber sealing.
When should an exhaust valve seat be replaced?
Replacement is recommended when the original seat becomes worn, cracked, recessed, damaged during engine failure, or during cylinder head rebuilding when inspection indicates replacement is necessary.
Is this a genuine Cummins part?
Yes. Cummins 3904105 is a genuine OEM Cummins exhaust valve seat manufactured to factory specifications.
Can I install this myself?
Valve seat installation typically requires specialized machining equipment and should generally be performed by a qualified machine shop familiar with diesel cylinder head rebuilding.
Do I need any related parts?
During cylinder head service, inspect the valves, guides, springs, seals, and related components and replace worn parts as needed to ensure reliable operation.
