OTTO Excavator Spare Parts Yc 4Hf1 Oil Overflow Valve 8973288590 897328-8590 8-97328859-0 For Isuzu This product is an oil overflow valve designed for the Isuzu engine model 4HF1 in the YC excavator. The part numbers associated with it are 8973288590, 897328-8590, and 8-97328859-0. The overflow valve plays a crucial role in regulating and maintaining the oil pressure within the engine, ensuring efficient functioning of the specified equipment.