Caterpillar original Fuel Injector Cross Reference 4W7017 0R1745, Pencil Fuel Injector 4W7018, Replacement for OEM 0R3422, fits 3304 3306 3406B 3408 Engines for Excavator original new injector

At the final stage of diesel fuel delivery, the Caterpillar 4W7018 (4W-7018) fuel injector nozzle provides precision metering and atomization for demanding CAT engine applications. Manufactured from heat-treated alloy steel using precision CNC machining, it incorporates a precision-ground needle valve and calibrated nozzle orifices. Its OEM-equivalent design is engineered to support an optimized spray pattern, accurate fuel delivery, wear resistance, corrosion protection and long service life in high-pressure fuel injection environments.

As high-pressure fuel lifts the needle valve and passes through the nozzle orifices, it is atomized into fine droplets for mixing with compressed air in the combustion chamber. This controlled process supports improved combustion efficiency, fuel economy, stable engine operation, reduced emissions and cold-start performance, while needle-valve closure helps prevent fuel leakage. The nozzle is frequently selected for injector rebuilding, engine overhauls, fleet maintenance programs and aftermarket replacement projects.

The 4W7018 is commonly referenced for CAT 3304, 3306 and 3406 engine families, as well as industrial, marine, generator-set and heavy-equipment diesel engines. Equipment sectors include excavators, wheel loaders, bulldozers, motor graders, mining trucks, diesel generators, marine propulsion engines, industrial power units and agricultural machinery. Before ordering, verify the injector assembly, engine serial, arrangement and equipment serial numbers. For service, use clean components, verify injector opening pressure, follow Caterpillar service manual specifications and perform bench testing whenever possible.