Komatsu 20Y-03-21531 Lower Radiator Hose Assembly

The 20Y-03-21531 lower radiator hose is a critical component of the engine cooling system for Komatsu 6D95 series engines. It connects the radiator outlet to the water pump inlet, facilitating the flow of cooled coolant back into the engine block. Constructed from high-grade EPDM rubber compound reinforced with synthetic textile cords, it withstands operating temperatures ranging from -40°C to 125°C and cooling system pressures up to 110 kPa (16 psi). The hose features precision-molded ends to ensure leak-free sealing on OEM radiator and water pump flanges. Designed as a direct replacement for Komatsu part numbers 20Y-03-21531 and 20Y0321531, it restores factory cooling performance and prevents overheating in demanding construction environments. This hose assembly is validated for fitment on PC200-6, PC200LC-6, PC210-6, PC210LC-6, and PC220-6 excavator models equipped with the 6D95 engine. Installation requires standard hand tools and new coolant clamps. Regular inspection for cracks, swelling, or softening is recommended during scheduled maintenance intervals to ensure cooling system integrity.