Cummins 138999 Fuel Pump Torque Spring

The Cummins 138999 is a fuel pump torque spring designed for PT fuel systems on heavy-duty diesel engines. It provides controlled compressive force to regulate fuel pump torque, ensuring accurate fuel injection timing and metering. This compression spring is constructed from high-strength spring steel with a color-coded finish (Green/Yellow/Blue) for identification. It features approximately 5.41 active coils. The component is critical for maintaining fuel delivery precision in Cummins PT fuel pump assemblies. Primary applications include non-certified 11-liter M11 engines, as well as N14, NT855, NH, NT, K19, K38, K50, QSK, L10, V28, QSX, QSM, 4BT, 6BT, QSB, QSC, and ISF engine series. Aftermarket cross-references include Interstate-McBee M-138999 and Reliance K138999. Verify engine serial number (ESN) for exact fitment due to configuration variations.