Product Description
Genuine Cummins
Cummins 3934396 — Vacuum Pump Oil Supply Line (Pump → Engine)
MPN: 3934396 | Also Known As: vacuum pump oil feed line, flexible hose | Location: Engine block to vacuum pump (lubrication supply)
Why This Part
- ✓ OE flexible hose that feeds engine oil to the vacuum pump for proper lubrication.
- ✓ Direct-fit replacement for late 2nd-Gen Ram 5.9L (1998.5–2002).
- ✓ Durable construction to handle heat and vibration.
- ✓ Restores factory reliability when the original line leaks or cracks.
OE Fit Stock Replacement 1 Per Vehicle
Quick Specs
| Type | Vacuum pump oil supply line (flexible hose) |
|---|---|
| OE Part # | 3934396 |
| Routing | Engine block → vacuum pump |
| Qty Required | 1 per vehicle (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1998.5–2002 | Ram 5.9L ISB (24V) | Ram 2500/3500 |
Industrial/Off-Highway: Appears on various ISB/QSB 5.9 applications—verify by ESN before ordering.
Often Paired With
- Vacuum Pump Reseal Kit: Cummins 4089742
- New sealing washers/banjo seals (replace if damaged)
- Fresh oil & filter after contamination or major service
What’s In The Box
- (1) Genuine Cummins Vacuum Pump Oil Supply Line (3934396)
- Seals/hardware sold separately (see “Often Paired With”).
Install Tips
- Route per factory path; avoid chafe/heat points and verify clearances.
- Use new sealing washers; torque fittings to spec and check for leaks on warm-up.
- If the old line failed, inspect the vacuum pump and flush any contaminants.
FAQ
WILL THIS FIT MY 1998.5–2002 5.9L CUMMINS RAM?Yes—this is the OE oil feed line for late 2nd-Gen 5.9L (1998.5–2002). Always confirm by VIN/ESN.
IS THIS THE LINE FROM THE ENGINE BLOCK TO THE VACUUM PUMP?Correct—this flexible hose supplies lubrication oil from the engine to the vacuum pump.
DO I NEED ANY EXTRA SEALS OR WASHERS?Yes—replace any copper/banjo sealing washers and O-rings disturbed during service to prevent leaks.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3934396 with factory routing and fitting geometry.
WHAT IF MY TRUCK IS A 12-VALVE (1994–1998)?Earlier 12-valve trucks use different lines. This listing targets 1998.5–2002 24-valve applications.
