Komatsu 209-03-77291 Radiator Hose Assembly

The 209-03-77291 is a heavy-duty reinforced rubber radiator hose assembly manufactured to Komatsu engineering standards for engine cooling circuits on large hydraulic excavators. It transmits coolant between the engine block and radiator core, maintaining thermal stability under continuous high-load operation in construction and mining environments. Constructed from heat-resistant synthetic rubber with textile reinforcement, the hose withstands elevated coolant temperatures and system pressure cycles. The assembly includes formed ends for precise routing within the engine compartment of PC750-6, PC750-7, PC800-6, PC800-7, and SE variants. Designed as a direct OEM replacement, it ensures seal integrity at flange connections and resists degradation from coolant additives and ozone exposure.