OTTO Excavator Parts Yc 4Hf1 Thermostat Tube 8943425740 894342-5740 8-94342574-0 For Isuzu The OTTO Excavator Parts YC 4HF1 Thermostat Tube, with part number 8943425740, is a component designed for Isuzu engines. It facilitates the proper circulation of coolant, contributing to the efficient cooling system performance.