3609833 3821579 Lubricating oil pump (Cummins) Replacement for NH/NT855 G855 CM855 K38

• Heavy-duty precision fit: 100% compatible with original engine structures like NH/NT855 and K38. Fully matches oil circuit interfaces and mounting holes, enabling direct replacement without engine modifications. Eliminates leakage and unstable oil pressure issues caused by aftermarket part misalignment, achieving over 99% compatibility success rate.
• Heavy-Duty Durable Materials & Craftsmanship: 3609833 features a high-strength cast iron pump body + 20CrNiMo carburized and quenched gears (surface hardness HRC60-65). while model 3821579 upgrades to a ductile iron pump body + wear-resistant gear assembly. Wear resistance exceeds standard aftermarket parts by over 50%, withstanding dusty and continuously vibrating environments in mining, construction, and similar applications. Mean Time Between Failures (MTBF) exceeds 3000 hours.
• High-load performance stability: Optimized flow path design for heavy-duty demands of high-horsepower engines. 3609833 delivers stable 3.0-5.0 bar oil pressure. Model 3821579 adapts to higher-power K38 engines, boosting oil pressure to 3.5-5.5 bar. Even during continuous full-load operation (100% power output), it ensures adequate lubricant supply, reducing component wear rates by over 40%.​
• Effortless aftermarket replacement: Supports “plug-and-play” installation, allowing professional technicians to complete the swap in 2-3 hours. Leveraging Cummins' global authorized service network, it rapidly addresses emergency repair needs in mining sites and remote construction areas, minimizing equipment downtime losses.

1. Are 3609833 and 3821579 interchangeable? How to distinguish compatible models?
They are not fully interchangeable. Key compatibility differences are as follows:
① 3609833 is compatible with Cummins NH855, NT855, G855, and CM855 series engines; ② 3821579 primarily targets K38 series engines and is only compatible with select upgraded NT855 models. Identification method: Verify the engine model via the nameplate, or contact a Cummins service station to provide the VIN code for compatibility list verification to prevent mismatches causing incorrect oil pressure.

2. Are both pumps only for aftermarket replacement?
Primarily positioned as OEM-grade aftermarket replacements. Their structure and materials match OEM parts, meet performance standards, and offer higher cost-effectiveness. Suitable for new equipment installations or overhauling old equipment.

3. What are the core advantages over standard aftermarket pumps?
① Compatibility: 100% alignment with OEM oil passages and mounting holes, eliminating leakage and unstable pressure risks. ② Durability: High-strength cast iron/ductile iron pump body + alloy gears deliver 50%+ improved wear resistance and MTBF exceeding 3000 hours. ③ Heavy-load adaptation: Optimized flow paths for high-horsepower engines ensure stable oil pressure under full load, eliminating aftermarket “heavy-load pressure drop” issues.

4. What are the key installation precautions?
① Must be installed by personnel certified in heavy-duty engine repair; ② Inspect pump body for damage, verify gear functionality, and ensure all accessories are present upon unpacking; ③ Clean engine oil line interfaces before installation to prevent contaminants entering the pump body; ④ Tighten bolts to specified torque (refer to engine maintenance manual) to prevent loosening and vibration; ⑤ Perform pressure retention test post-installation (5 min without leakage), then trial run to confirm oil pressure within model-specific standard range (3609833: 3.0-5.0 bar; 3821579: 3.5-5.5 bar).

5. Are there specific requirements for compatible engine oil grades? Can different specifications be mixed?
Only SAE 15W-40/20W-50 (API CI-4 or higher standard) diesel engine oil is supported. Mixing oils of different viscosities or brands is strictly prohibited, as it accelerates gear wear and clogs oil passages. Such damage is not covered under warranty.

6. How should uninstalled pump bodies be stored and transported?
Store in a moisture-proof, sun-protected environment away from corrosive substances. Do not store for more than 3 months; reseal integrity must be verified after this period. Transportation requires securement in reinforced wooden crates to prevent gear misalignment from severe vibration. Strictly prohibit co-loading with heavy objects that may cause crushing.

7. How to troubleshoot abnormal oil pressure (too high/too low) during operation?
Low oil pressure: ① Top up engine oil to standard level; ② Clean the inlet filter screen (often clogged with dust); ③ Check if the pump pressure regulator valve is stuck; disassemble and clean the valve core; ④ If the issue persists, inspect the engine oil passages for leaks.
High Oil Pressure: ① Check if the oil viscosity is too high (e.g., incorrect grade used in low temperatures); ② Pressure regulator valve failure; replace with an OEM regulator valve; ③ Oil passage blockage; clean the engine oil passages.

8. What are the possible causes of oil leakage from the pump body? ​
① Improperly seated or damaged gasket—replace gasket and tighten to specified torque; ② Pump housing interface mismatched with engine oil passages (incorrect model)—replace with compatible pump housing; ③ Sand holes in pump casting (quality defect)—request replacement under warranty. ​

9. Is severe pump housing overheating normal under heavy load?​
Slight heating (≤80°C) is normal. If temperature exceeds 100°C or becomes too hot to touch, investigate: ① Insufficient oil volume or incorrect oil grade; ② Excessively small gear meshing clearance (misalignment during installation); ③ Oil circuit blockage causing pump overload. Shut down for inspection to prevent component burnout.

10. How to extend pump body service life?
① Replace specified oil every 15,000 km / 1,000 hours; ② Clean the inlet filter screen monthly (every 2 weeks in harsh environments like mining); ③ Avoid prolonged full-load idling to reduce no-load wear; ④ Preheat the engine to above 5°C before starting the oil pump in winter.