The Hyundai HL780-3A is a robust Wheel Loader designed for demanding material handling, construction, and earthmoving applications. Engineered with a powerful Cummins QSB6.7 diesel engine producing 217 HP, it features an Automatic Power Shift transmission and 4WD for optimal performance. Its substantial operating weight of 23,500 kg, combined with a 3.8 m³ standard bucket capacity and a towing capacity of 10,000 kg, makes it a reliable and efficient heavy equipment solution. The articulated steering, with an angle of ±40 degrees, enhances maneuverability in challenging environments, ensuring productivity and operational excellence. This Service & Operating manual provides comprehensive guidance for the Hyundai HL780-3A Wheel Loader. It covers essential maintenance procedures, including lubrication details such as recommended API CJ-4 engine oil and a 24 L oil capacity, along with troubleshooting steps and detailed technical specifications. Safety guidelines and operating parameters are also included to ensure safe and efficient operation. This manual is an indispensable resource for owners, mechanics, and technicians, enabling them to maintain, service, and repair the vehicle effectively, thereby maximizing its lifespan and operational readiness.