Description:
The Cummins Expansion Plug 3905368 is a genuine OEM block plug designed to seal service openings or freeze-plugs in Cummins engines, especially the ISB/QSB 6.7L series. It ensures that coolant, oil or other fluids do not escape the engine block, maintaining system integrity. It is a small but vital engine component, using the correct plug helps prevent leaks, engine damage and downtime.
Features:
Part#: 3905368
Application / Fitment: Used in Cummins ISB / QSB 6.7L engines (and potentially other Cummins industrial blocks)
Function: Expansion plug / freeze-plug / block plug – seals an unused or service hole in engine block or other casting
Material / Construction: Steel or metallic material in aftermarket listing: e.g., “0.385” OD x .0490” Thk x 0.037” Depth” steel plug
Dimensions: 0.385” (9.78mm) OD × 0.490” (12.45mm) depth × 0.037” (0.94mm) thickness
Brand: Cummins
