Product Description
Cummins 3941156 — Genuine VP44 Overflow Valve (Check Valve)
MPN: 3941156 | Also Known As: overflow valve, return line check valve, case pressure regulator | Cross-Refs (ID): Bosch 1 467 445 003; 1417413047; 1467445003; Cummins 4089577
Restore proper VP44 case pressure and fuel system reliability. The genuine Cummins 3941156 overflow valve installs on the return line at the VP44 injection pump and regulates internal pump pressure for clean starts, stable idle, and consistent power. Direct-fit OE part for 1998.5–2002 Ram 2500/3500 5.9L 24-valve and widely used on ISB/QSB industrial variants.
Features & Benefits
- OE regulation of VP44 case pressure to protect the pump and maintain fueling.
- Direct-fit replacement—no adapters; threads and seat match the factory pump fitting.
- Fixes common symptoms: hard starts, low power, erratic idle from a stuck-open valve.
- Durable, zinc-plated body for corrosion resistance and long service life.
Verified Fitment (Automotive)
| Year Range | Engine | Fuel System | Chassis |
|---|---|---|---|
| 1998.5–2002 | 5.9L ISB | VP44 (24-valve) | Ram 2500 / Ram 3500 |
Industrial/Off-Highway: Cummins catalogs 3941156 as a Check Valve used primarily on Stage 2 / BS3 5.9L ISB/QSB engines—verify by ESN for equipment builds.
Specifications
- Type: Return-side check/overflow valve for VP44
- OE Part Number: 3941156
- Thread: 9/16 – 18 (typical VP44 overflow valve thread)
- Location: VP44 injection pump, return/overflow port
- Sealing Washers: Cummins 3918192 (2 required, sold separately)
- Quantity Required: 1 per engine
Often Paired With
- Sealing washers (banjo): Cummins 3918192 (two per valve)
- Fuel lift pump (stock replacement or performance upgrade)
- Fuel pressure gauge (verify VP44 supply/case pressure after install)
What’s In The Box
- (1) Genuine Cummins VP44 Overflow Valve / Check Valve (3941156)
- Sealing washers sold separately (some kits include 2 washers—see notes).
Installation Tips
- Relieve fuel pressure; clean mating surfaces. Replace both sealing washers.
- Torque to spec; verify for leaks. Prime the system and monitor fuel pressure during the first start.
- If low pressure persists, test the lift pump and filter; check for restrictions.
FAQ
WILL THIS FIT MY 1998.5–2002 5.9L 24-VALVE RAM?
Yes—3941156 is the OE overflow valve for VP44-equipped 5.9L trucks in this range.
WHERE DOES IT INSTALL?
On the VP44’s return (overflow) port—it regulates internal pump case pressure.
DO I NEED NEW SEALING WASHERS?
Yes—use two 3918192 sealing washers (most leaks trace back to reusing old washers).
WHAT ARE THE CROSS-REFERENCE NUMBERS?
Common IDs include Bosch 1 467 445 003, 1417413047, 1467445003, and Cummins 4089577.
IS THIS A GENUINE CUMMINS PART?
Yes—OE Cummins 3941156.
