Product Description
Genuine Cummins
Cummins 3931523 — Fuel Lift Pump Elbow Hose (Heater → Transfer Pump), 5.9L 12-Valve
MPN: 3931523 | Also Known As: heater-to-lift pump hose, fuel pre-heater elbow hose, molded hose | Replaces/Old PN: 3921680
Why This Part
- ✓ OE molded elbow that connects the fuel pre-heater/pre-filter to the mechanical transfer (lift) pump.
- ✓ Direct-fit for 1994–1998 Dodge Ram 2500/3500 5.9L 12-valve (P7100).
- ✓ Prevents air intrusion and hard-start issues common to aged hoses.
- ✓ Durable Cummins rubber compound for heat, fuel, and vibration resistance.
OE Fit Stock Replacement 1/2" ID (~0.497")
Quick Specs
| Type | Molded fuel hose (elbow, heater→lift pump) |
|---|---|
| OE Part # | 3931523 (old PN 3921680) |
| Inner Diameter | ~0.497" (1/2" nominal) |
| Qty Required | 1 per vehicle (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1994–1998 | 5.9L 12-Valve Cummins (P7100) | Dodge Ram 2500/3500 |
Industrial/Off-Highway: Used on Tier 1 5.9L B-series applications—always confirm by ESN.
Often Paired With
- Mechanical Transfer (Lift) Pump: Cummins 4988747 (or Alliant AP4988747)
- Fuel heater service/seals if removing pre-heater assembly
- Fresh fuel hose clamps (replace aged/brittle hardware)
What’s In The Box
- (1) Genuine Cummins Molded Hose (3931523)
- Clamps and adjacent hoses sold separately.
Install Tips
- Depressurize/prime the fuel system per factory procedure.
- Use new clamps and ensure the hose is fully seated on barbs.
- After install, prime the system and check for seepage/air leaks.
FAQ
WILL THIS FIT MY 1994–1998 12-VALVE CUMMINS RAM?Yes—this elbow connects the pre-heater/pre-filter housing to the mechanical lift pump on ’94–’98 5.9L 12-valve trucks (verify by VIN/ESN).
WHAT’S THE DIFFERENCE BETWEEN 3931523 AND 3921680?3921680 is the older number; 3931523 is the current OE molded elbow hose.
WHAT SIZE IS THE HOSE?Approx. 1/2" inner diameter (~0.497"). Use quality clamps for a proper seal.
DO I NEED TO REPLACE THE LIFT PUMP TOO?Not necessarily. Replace the pump (e.g., Cummins 4988747) if it shows leaks, low pressure, or age-related failure.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins molded hose 3931523 for proper fit, materials, and durability.
Product Videos
Custom Field
Vehicle Year 1994,1995,1996,1997,1998
Vehicle Make DODGE
ENGINE 5.9L
Part Type Factory Lift Pump Elbow Hose
