Cummins 3923084 — Genuine Vacuum Pump Oil Supply Line (Pump to Engine) for 5.9L 12V

MPN: 3923084  |  Also Known As: vacuum pump oil feed line, flexible hose  |  Application: Oil supply from engine block to vacuum pump

Genuine Cummins pre-formed flexible hose that supplies pressurized engine oil to the vacuum pump. Built to OE spec for routing, fittings, and durability. Direct-fit on 1994–1998 5.9L 12-valve (6BT) Ram 2500/3500.

Features & Benefits

• OE fit & pre-formed bends for clean routing and leak-free connections.
• OEM materials resist heat, oil, and engine vibration.
• Protects the vacuum pump by maintaining proper lubrication.
• Direct replacement—no adapters or trimming required.

Verified Fitment (Automotive)

Industrial/Off-Highway: Used primarily on Tier 1/BS3 5.9L B-Series engines—verify by ESN for non-automotive equipment.

Specifications

• Type: Flexible engine oil supply hose (vacuum pump feed)
• OE Part Number: 3923084
• Ends/Fittings: Pre-formed OEM hose with factory-style terminations
• Quantity Required: 1 per vehicle (sold individually)

Often Paired With

• Vacuum pump reseal kit: Cummins 4089742 (’94–’02)
• Vacuum pump cover/delete plate (race only): Cummins 3914868 (’94–’02)
• Fresh engine oil & filter: recommended after oil-system repairs

What’s In The Box

• (1) Genuine Cummins Vacuum Pump Oil Supply Line (3923084)

Installation Tips

• Clean mating surfaces and replace any crush washers or sealing hardware as required.
• Route to match OEM path; avoid chafe points and excessive twist.
• Inspect pump shaft seal and front cover area; reseal pump if any seepage is present.
• Start, check for leaks at idle and again after a road test.

FAQ

WILL THIS FIT MY 1994–1998 5.9L 12-VALVE RAM?

Yes—3923084 is the OE pump-to-engine oil feed hose for 1994–1998 5.9L 12-valve Ram 2500/3500. Always confirm by VIN/ESN.

DOES THIS HOSE INCLUDE FITTINGS OR SEALS?

The hose is pre-formed to OE spec. Reuse or replace sealing hardware per factory procedure; replace crush washers if equipped.

SHOULD I REPLACE THIS WHEN SERVICING THE VACUUM PUMP?

Yes—replacing the oil feed hose along with a pump reseal or pump replacement helps prevent future leaks and premature pump wear.

IS THIS THE SHORT FLEXIBLE OIL FEED FROM THE BLOCK TO THE VACUUM PUMP?

Correct—this is the flexible oil supply line that feeds the vacuum pump from the engine block on 12-valve applications.

IS THIS AN OEM CUMMINS PART?

Yes—genuine Cummins part 3923084 for proper fit, routing, and durability.