Product Description
CUMMINS 3923084 OEM VACUUM PUMP OIL SUPPLY LINE – 5.9L 12V (1994–1998) is the genuine Cummins flexible oil feed hose that runs from the engine block to the vacuum pump on 1994–1998 Dodge/Ram 2500 and 3500 trucks with the 5.9L 12-valve Cummins. This pre-formed hose restores proper lubrication to the vacuum pump and eliminates messy leaks caused by cracked, hardened, or kinked originals.
Over time, heat, vibration, and age can cause the factory hose to seep or split, starving the vacuum pump of oil and coating the front of the engine with oil mist. Replacing it with genuine CUMMINS 3923084 ensures the correct length, bend profile, and flare/crimp geometry for a clean, no-drama installation and long-term reliability.
Key Features
- Genuine Cummins OEM hose – not a generic replacement.
- Feeds pressurized engine oil from the block to the vacuum pump for proper lubrication.
- Pre-formed flexible hose with correct length and routing for 5.9L 12V applications.
- Designed for 1994–1998 Dodge/Ram 2500/3500 5.9L 12-valve Cummins trucks.
- Also used on Tier 1 5.9L B-series industrial applications where equipped.
- Direct-fit replacement – no cutting, guessing, or adapting required.
Fitment
- 1994–1998 Dodge/Ram 2500 5.9L Cummins 12-valve (vacuum pump equipped)
- 1994–1998 Dodge/Ram 3500 5.9L Cummins 12-valve (vacuum pump equipped)
- 5.9L B-series Tier 1 industrial/Construction applications using Cummins 3923084 flexible hose
Location / Function: Short flexible oil supply hose from engine block oil gallery to the vacuum pump inlet. If this hose leaks, collapses, or plugs, the vacuum pump can lose lubrication and fail prematurely.
Often Paired With (Cummins Genuine Cross-Reference)
- CUMMINS 4089742 OEM VACUUM PUMP RESEAL KIT – 5.9L CUMMINS (1994–2002)
- CUMMINS 3934396 OEM VACUUM PUMP OIL SUPPLY LINE (PUMP TO ENGINE) – RAM 5.9L (1998.5–2002)
- CUMMINS 3914707 OEM VACUUM PUMP TO POWER STEERING PUMP JAW COUPLING HUB – RAM 5.9L (1994–2002)
- CUMMINS 3932321 OEM OIL FITTING – MALE CONNECTOR (ENGINE BLOCK TO TEE) – RAM 5.9L 12-VALVE (1994–1998)
- CUMMINS 3923083 OEM P7100 INJECTION PUMP OIL FEED LINE – 5.9L 12V (1994–1998)
When Should You Replace 3923084?
- Visible cracks, swelling, or hardening of the hose.
- Oil seepage around hose crimps or along the hose body.
- Oil mist or drip marks at the vacuum pump or along the front cover.
- Any time the vacuum pump is resealed or replaced – best practice to renew the feed hose.
FAQ
WILL THIS HOSE FIT MY 1994–1998 5.9L 12-VALVE RAM?
Yes. CUMMINS 3923084 is the OEM vacuum pump oil supply hose for 1994–1998 Dodge/Ram 2500 and 3500 trucks equipped with the 5.9L 12-valve Cummins and a gear-driven vacuum pump. Always verify by VIN/engine serial number if you are unsure.
IS THIS THE SHORT FLEXIBLE LINE FROM THE BLOCK TO THE VACUUM PUMP?
Correct. This hose connects the pressurized oil passage in the engine block to the inlet on the vacuum pump. It does not go from the pump to the power steering pump – that function uses other components such as the CUMMINS 3914707 jaw coupling hub and related hardware.
DO I NEED TO REPLACE THIS WHEN I RESEAL OR REPLACE THE VACUUM PUMP?
It is strongly recommended. A fresh OEM hose helps ensure consistent oil supply and reduces the chance of future leaks. Many owners replace 3923084 at the same time as a CUMMINS 4089742 vacuum pump reseal kit or a replacement vacuum pump.
IS THIS A GENUINE CUMMINS PART OR AFTERMARKET?
This listing is for a genuine Cummins OEM hose, part number 3923084. Buying OEM ensures correct routing, high-temperature hose materials, and long-term durability in heavy-duty use.
WHAT ELSE SHOULD I CHECK WHILE I’M IN THERE?
Inspect the vacuum pump shaft seal, the pump-to-power-steering coupling, and the associated oil fittings and tees. Upgrading or replacing components such as CUMMINS 3932321 oil fitting and CUMMINS 3923083 P7100 oil feed line while the system is open can save time and prevent future leaks.
Specifications for cummins 3923084
| Brand | Cummins Genuine Parts |
| Part Number | 3923084 |
| Product Type | Vacuum Pump Oil Supply Line (Flexible Hose) |
| Engine Application | 5.9L Cummins B-series 12-valve, 1994–1998 Dodge/Ram 2500/3500; Tier 1 5.9L B-series industrial where specified |
| UPC | Not publicly listed by Cummins |
| GTIN | Not publicly listed by Cummins |
| Cross Reference | Cummins 3923084 (OE); commonly referenced in systems with Cummins 3923083, 3932321, 3934396, 4089742 |
| E-Codes / Emissions | Not emissions-certified; engine lubrication component only |
| Material | Oil-rated flexible hose with crimped steel fittings (OEM specification) |
| Shipment Weight | Approx. 0.2 lb (small parcel) |
| Typical Packaging | One hose per package; sealed OEM Cummins packaging |
| Country of Origin | Not specified by manufacturer (varies by production batch) |
| Prop 65 Warning | Not specifically listed; treat as standard automotive service part – avoid prolonged skin contact with used engine oil |
