Product Description
Cummins 3925009 — Oil Pressure Regulator Compression Spring (Oil Filter Housing)
MPN: 3925009 | Also Known As: oil pressure regulator spring, oil pressure relief spring | Location: Oil filter housing/regulator assembly
Why This Part
- ✓ Restores proper oil pressure regulation by returning the regulator to OE spring tension.
- ✓ Direct-fit replacement for B-Series/ISB 5.9L and early ISB 6.7L (see fitment).
- ✓ OE material and rate for stable hot-idle and cruise pressure.
- ✓ Ideal when servicing the regulator valve & plunger after low-pressure issues.
Quick Specs
| Type | Oil pressure regulator compression spring |
|---|---|
| OE Part # | 3925009 |
| Assembly | Oil filter housing / pressure regulator |
| Qty Required | 1 per engine (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1994–1998 | 5.9L 12-Valve (6BT) | Ram 2500/3500 |
| 1998.5–2002 | 5.9L 24-Valve (ISB VP44) | Ram 2500/3500 |
| 2003–2007 | 5.9L ISB (Common-Rail) | Ram 2500/3500 |
| 2007.5–2012 | 6.7L ISB (pre-EPA13) | Ram 2500/3500 |
Notes: For many 2013+ 6.7L applications, the regulator spring updates to Cummins 5285537. Always confirm by VIN/ESN.
Often Paired With
- Oil Pressure Relief Valve: 3936365
- Regulator Plunger: 3918428
- Filter Head (’98.5–’02 24V): 3934303
- Filter Head (’03–’18 CR): 5289557
- Gaskets (5.9L ’03–’07): 3864458 (cooler→filter), 4895742 (cooler→block)
- Gaskets (6.7L ’07.5+): 3974127 (cooler→filter), 2830559 (cooler→block)
What’s In The Box
- (1) Genuine Cummins Oil Pressure Regulator Compression Spring (3925009)
- Valve, plunger, gaskets & housings sold separately (see above)
Install Tips
- Inspect the regulator bore and plunger (3918428) for scoring; replace as needed.
- Verify oiling-system cleanliness after any failure; change oil & filter.
- Warm-idle pressures vary by build; compare to OEM spec after install.
FAQ
WILL THIS SPRING FIX LOW OIL PRESSURE?It restores the regulator’s spring force, but low oil pressure can also result from a worn plunger/valve, pump wear, leaks, or bearing clearance. Inspect related parts (3936365 valve, 3918428 plunger) and verify with a mechanical gauge.
WHERE DOES THIS SPRING INSTALL?Inside the oil filter housing as part of the pressure regulator assembly.
WHAT YEARS/ENGINES DOES 3925009 COVER?Common on 5.9L (1994–2007) and early 6.7L (2007.5–2012) ISB applications; 2013+ often uses updated spring 5285537—always confirm by VIN/ESN.
IS THIS A GENUINE CUMMINS PART?Yes—OE Cummins 3925009 with factory spring rate and dimensions.
SHOULD I REPLACE THE RELIEF VALVE TOO?Recommended if the valve is sticking or worn. The matching OE valve is 3936365; replace the plunger 3918428 if scored.
