Cummins Lubricating Oil Pump | P/N 3644520

Cummins Lubricating Oil Pump | P/N 3644520 PRODUCT OVERVIEW
Cummins Lubricating Oil Pump | P/N 3644520 is listed around primary identifier 3644520. This listing is designed to help buyers identify the correct part by part number, product identity, and application details. PART NUMBER AND PRODUCT IDENTITY
Primary Part Number / Identifier: 3644520
Product Type: Lubricating Oil Pump
Brand / Manufacturer: Cummins APPLICATIONS
Cummins lubricating oil pump for industrial/commercial engine applications; Truckomotive specifically associates 3644520 with QSK45, but confirm by ESN.
Engine / Equipment Family: Cummins industrial engine lubricating oil pump family; QSK45 reference observed INSTALLATION / PROGRAMMING / FITMENT NOTES
No ECM programming; pump tag and system configuration must be checked. SEND US YOUR OLD PART DETAILS
Send us a clear photo of your old part label/tag or part number before ordering, and our team will help confirm the correct match.
ORDER BENEFITS
FREE worldwide shipping is included with every OrderECM product. Your order is also backed by a 30-day money-back guarantee and a 365-day replacement warranty. CONDITION AND WARRANTY
Condition and availability should be confirmed before ordering. All components are inspected prior to dispatch.
365-Day Replacement Warranty | 30-Day Money-Back Guarantee | Free Worldwide Shipping via DHL, FedEx, or UPS ENGINE OIL PUMP — DIAGNOSIS AND INSTALLATION OIL PUMP FAILURE SYMPTOMS
Oil pump failure on large Cummins engines typically manifests as: low oil pressure warning at idle (normal warm idle pressure should be 15–30 psi minimum depending on engine), oil pressure that drops under load but recovers at idle, or — in severe cases — sudden loss of oil pressure with bearing damage. Oil pump wear develops gradually; the first indicator is usually lower-than-specification oil pressure at operating temperature. Confirm oil pump failure by: Measuring actual oil pressure with a calibrated mechanical gauge (not relying solely on the dashboard gauge, which may have its own sensor fault) Checking oil pump pickup tube for blockage or loose connection — a common and simple fault that mimics pump failure Measuring the pump internal clearance against the Cummins service specification (requires disassembly) OIL SYSTEM SERVICE
When replacing the oil pump on a QST30 or large Cummins engine: Replace the oil pump pickup tube O-ring and verify the tube is fully seated in the pump Flush the entire oil system before installing the new pump — old oil contamination shortens pump life Prime the pump with clean oil before installation to prevent dry-start damage Replace the full-flow oil filter and bypass filter at the same time After installation, crank the engine without fuel supply until oil pressure is confirmed before starting — use the prelube system if equipped Verify oil pressure at idle and at rated speed before returning to service