Cummins engine spare parts Fuel injection pump C3960900

Built as the “heart” of the 6BT/6CT engine’s fuel system, this injection pump delivers ultra-precise fuel metering and timing control. It adopts a Bosch-derived inline plunger design with electronic governor, achieving a fuel injection quantity tolerance of ±1% and injection timing accuracy of ±0.5° crankshaft angle. The 1200bar high injection pressure atomizes fuel into 5μm droplets, maximizing combustion efficiency and increasing engine power output by 8% compared to outdated pumps. For 6BT-powered construction loaders, this precision reduces fuel consumption by 10-12% during heavy-load operation, while minimizing unburned fuel and particulate emissions to meet EPA Tier 3 and China III standards

Engineered to endure the harsh operating conditions of medium-duty engines, the C3960900 pump features a rugged mechanical construction. The pump body is precision-cast from nodular cast iron (GGG50) with reinforced internal ribs, resisting deformation under 1200bar injection pressure and engine vibration (10-500Hz). The plungers and barrels are made of high-speed steel (HSS) with a surface hardness of HRC 62-65, ensuring wear resistance and a service life of ≥300,000km. A double-row angular contact bearing (sealed with high-temperature grease) supports the camshaft, reducing friction and ensuring smooth operation even at the engine’s maximum speed of 2800rpm. The pump’s built-in pressure relief valve prevents overpressure damage, adding an extra layer of protection

Optimized for diverse operating environments, the injection pump exhibits exceptional adaptability to temperature, fuel quality, and altitude. It operates reliably within a temperature range of -40℃ to 120℃, with a cold-start auxiliary heater that ensures smooth fuel delivery in frigid northern winters. The pump’s fuel inlet check valve and filter screen (20μm) prevent contaminants from entering the plunger assembly, making it compatible with low-quality diesel (sulfur content up to 500ppm) common in remote construction sites. It maintains stable injection performance at altitudes up to 4500m (e.g., mountainous mining areas), avoiding power loss caused by reduced air pressure. The pump’s seals use FKM rubber, resisting swelling from biodiesel (B20) and fuel additives

The C3960900 injection pump is designed for low maintenance and long-term cost savings. Its modular structure allows individual replacement of wear parts (plungers, seals) without replacing the entire pump, reducing repair costs by 60% compared to aftermarket alternatives. A centralized lubrication system with a sight glass simplifies oil level checks, while the electronic governor’s self-diagnostic function (via J1939) enables quick troubleshooting of injection issues—reducing downtime by 40%. By ensuring precise fuel delivery, the pump extends injector service life by 30% and prevents costly engine damage (e.g., piston scoring from lean combustion). Backed by a 2-year/250,000km Cummins warranty, it provides reliable performance for medium-duty applications, minimizing operational costs for fleet and equipment owners