Product Description
CUMMINS 3906697 OEM WATER INLET CONNECTION SEAL (RECTANGULAR RING O-RING) – 5.9L/6.7L (1994–2025)
OEM, GENUINE CUMMINS, WATER INLET SEAL, RECTANGULAR RING, COOLANT SEAL, DIESEL TRUCK, 5.9L CUMMINS, 6.7L CUMMINS, COOLANT SYSTEM, RADIATOR INLET, LOWER INLET ADAPTER, 3906697, COOLANT LEAK PREVENTION
This is the genuine Cummins 3906697 rectangular ring seal (water inlet connection O-ring) — the OE-spec sealing ring that fits between the lower radiator inlet adapter (water inlet elbow) and the engine block on 5.9L and 6.7L Cummins engines from 1994 through 2025. When replacing or servicing your coolant inlet adapter, this seal ensures a tight, leak-free connection and restores the factory-fit coolant path. Direct-fit for Dodge/RAM 5.9L & 6.7L (1994–2025); also commonly used on 4BT, 6BT, ISB, and QSB industrial/ off-highway engines using the same adapter design (always verify by ESN).
Fitment & Application
- 5.9L Cummins (1994–2007) — RAM 2500/3500 12V & 24V engines
- 6.7L Cummins (2007.5–2025) — RAM 2500/3500 24V ISB engines
- Industrial / Off-Highway Engines — 4BT, 6BT, ISB, QSB series using the same water inlet adapter design (verify by ESN)
- Sold individually — one seal required per engine when servicing water inlet connection.
Cross Reference / Alternate Part Numbers
- 3901467
- 4983908
FAQ
WILL THIS FIT MY 5.9L OR 6.7L RAM? Yes — this is the OEM-spec seal designed for the water inlet connection on 5.9L (1994–2007) and 6.7L (2007.5–2025) Cummins engines. Always verify by VIN or ESN.
WHERE DOES THIS SEAL INSTALL? This seal installs between the lower radiator inlet adapter (water inlet elbow) and the engine block — sealing the coolant inlet to prevent leaks.
HOW MANY DO I NEED? One per engine. Replace the seal any time the inlet adapter is removed or a leak is present.
IS THIS A GENUINE CUMMINS PART? Yes — this is the OEM seal sold by Cummins under part number 3906697.
DOES THIS ALSO FIT INDUSTRIAL ENGINES? Yes — many 4BT, 6BT, ISB, QSB and other industrial/ off-highway Cummins engines that use the same adapter design can utilize this seal. Always confirm fitment by engine serial number (ESN) before ordering.
What’s in the Box
- (1) Genuine Cummins rectangular ring seal (water inlet connection O-ring) — part # 3906697
Installation / Service Tips
- Clean both sealing surfaces thoroughly and remove all residue from the old seal.
- Lightly lubricate the new seal with a coolant-safe lubricant to help it seat evenly.
- When reinstalling adapter/housing bolts, tighten in a cross-pattern to spec. After assembly: refill coolant, bleed system, and check for leaks.
| Specifications for CUMMINS 3906697 | |
|---|---|
| Part Number | 3906697 |
| Description | Water Inlet Connection Seal (Rectangular Ring O-Ring) |
| Fitment | 5.9L / 6.7L Cummins (1994–2025), select 4BT/6BT/ISB/QSB industrial engines (verify by ESN) |
| Qty Required | 1 per engine |
| Location | Lower radiator inlet adapter / engine block coolant inlet |
| Cross-Reference Part Numbers | 3901467, 4983908 |
| Shipping Weight (approx.) | 0.01–0.20 lbs (varies by packaging) |
| UPC | |
| GTIN | |
| E-Codes | |
| Prop 65 Warning | |
