Product Description
Cummins 3906698 – Genuine Water Pump Rectangular Ring Seal for 5.9L & 6.7L Cummins
Keep your B-series Cummins cooling system sealed and leak-free with genuine CUMMINS 3906698. This rectangular ring seal sits between the water pump and the engine block on 5.9L and 6.7L applications, restoring OEM sealing so your Ram stays cool under towing, racing, and daily driving.
Why Choose Genuine Cummins 3906698?
- Direct OEM replacement for the water pump-to-block rectangular ring seal on B-series Cummins engines.
- Correct rectangular profile and material hardness to maintain clamp load and coolant pressure.
- Designed to handle diesel heat cycles, vibration, and extended towing or heavy-use operation.
- Prevents coolant leaks that can lead to overheating, cavitation, and premature water pump failure.
- Backed by Cummins engineering and quality control for consistent fit and performance.
Fitment – 5.9L & 6.7L Cummins (Ram & B-Series)
This seal is used primarily at the water pump mounting joint on BS3/B-series engines and Ram truck applications. Always verify by VIN or engine serial number (ESN).
- 1989–1993 Ram 2500/3500 – 5.9L 12V (6BT)
- 1994–1998 Ram 2500/3500 – 5.9L 12V (6BT)
- 1998.5–2002 Ram 2500/3500 – 5.9L 24V ISB (VP44)
- 2003–2007 Ram 2500/3500 – 5.9L ISB (24V Common-Rail)
- 2007.5–2018 Ram 2500/3500 – 6.7L ISB (Common-Rail)
Additional usage is cataloged across various Cummins industrial and off-highway engines, including select 4BT3.9, 6BT5.9, ISB3.9/ISB4.5 and QSB applications where this rectangular ring seal is specified for the water pump mounting interface. Always confirm by ESN before ordering.
Cross-Reference & Related Cummins Parts (Links to Cummins Only)
Use these genuine Cummins parts to complete your cooling or front-engine service:
- Water Pump Assembly: CUMMINS 5473238 OEM WATER PUMP KIT – 5.9L/6.7L (1989–2012)
- Timing/Front Cover Alignment: CUMMINS 3949326 OEM RING DOWEL – FRONT GEAR HOUSING/CYLINDER BLOCK ALIGNMENT – ISB 5.9L/6.7L (2003–2018)
- Cylinder Head Alignment: CUMMINS 3902343 OEM CYLINDER HEAD ALIGNMENT DOWEL (RING DOWEL) – 5.9L/6.7L CUMMINS (1989–2018)
- Oil System Service: CUMMINS 3949562 OEM OIL PICKUP TUBE GASKET – RAM 5.9L/6.7L (2003–2018)
Other cross-reference numbers commonly associated with this seal include OE references such as 04429698 and 4429698 (Dodge/Chrysler/Jeep/Ram), and aftermarket equivalents like PAI 121258 and Elring 073.720. These are listed for identification only; this listing is for a genuine Cummins part.
What’s Included
- (1) Genuine Cummins Rectangular Ring Seal – Part #3906698
Installation Tips
- Drain the cooling system and remove the water pump per the factory service manual.
- Thoroughly clean the pump pocket and block sealing surface; remove all old gasket material and corrosion.
- Lightly lubricate the new seal with clean coolant or a compatible lubricant to ease installation.
- Seat the seal squarely in the pocket, install the water pump, and torque fasteners to OEM spec.
- Refill with the correct coolant mixture and pressure-test the cooling system to verify a leak-free seal.
Specifications for cummins 3906698
| Brand | Cummins (Genuine OEM) |
|---|---|
| Part Number | 3906698 |
| Product Type | Rectangular ring seal – water pump to engine block |
| UPC | 193807288464 (cross-reference packaging, PAI 121258) |
| GTIN | 193807288464 |
| Shipping Weight | Approx. 0.02 lb (0.01 kg) |
| Package Dimensions | Approx. 3.90 in (W) x 3.90 in (D) x 0.30 in (H) |
| Engine Compatibility | Ram 5.9L 12V (1989–1998), 5.9L 24V ISB (1998.5–2002), 5.9L ISB common-rail (2003–2007), 6.7L ISB common-rail (2007.5–2018); plus select Cummins 4BT3.9, 6BT5.9, ISB3.9/ISB4.5/QSB applications where 3906698 is specified for the water pump. |
| Cross Reference (ID Only) | Dodge/Chrysler/Jeep/Ram 04429698, 4429698; DAF 1399688; Scania 2171598; PAI 121258; Elring 073.720; other cataloged gasket set references where 3906698 appears. |
| E-Codes | Not applicable (engine sealing component) |
| Country of Origin | Not specified by Cummins (global sourcing) |
| Prop 65 Warning | This product is an engine service component and may be used with fluids and chemicals that can expose you to substances recognized by the State of California to cause cancer or reproductive harm. For more information, visit www.P65Warnings.ca.gov. |
FAQ
WILL THIS FIT MY 1989–2018 RAM 5.9L OR 6.7L CUMMINS?
Yes. This rectangular ring seal is used on most 5.9L (1989–2007) and 6.7L (2007.5–2018) B-series/ISB Ram 2500 and 3500 applications where a rectangular water pump seal is specified. Always confirm by VIN or engine serial number (ESN) before ordering.
WHERE DOES THIS SEAL INSTALL?
It installs between the water pump and the engine block, sealing the coolant passage at the pump mounting surface. Any time the water pump is removed or replaced, this seal should be replaced as well.
DO I NEED TO REPLACE THE SEAL EVERY TIME I CHANGE THE WATER PUMP?
Yes. Once compressed, the old seal may not reseal properly. Installing a new rectangular ring seal with each water pump service is the best way to prevent leaks and come-backs.
IS THIS A GENUINE CUMMINS OEM PART?
Yes. This listing is for a genuine Cummins 3906698 rectangular ring seal, not a re-boxed or private-label part. You get OEM-quality materials and the correct geometry for B-series water pump applications.
WILL THIS WORK WITH AFTERMARKET WATER PUMPS?
In most cases, yes—provided the aftermarket pump follows OEM dimensions for the mounting pocket and sealing surface. If your pump is a stock-replacement design, this seal is typically the correct choice. When in doubt, verify pump compatibility with the manufacturer.
