This document pertains to the Hyundai HL780-3A, a robust piece of equipment engineered for demanding operational environments. While specific production years are not detailed, the 3A generation signifies a commitment to advanced design and performance. This manual covers essential aspects of its operation and maintenance, ensuring the longevity and efficiency of the machinery. This comprehensive factory service and repair manual provides detailed guidance for owners, technicians, and mechanics. It encompasses in-depth information on maintenance procedures, troubleshooting for various systems including the QSM11 engine with fault code data, and technical specifications. Coverage extends to the powertrain, brake, steering, and work equipment systems, along with the electrical system and its components. Safety hints and operation checkout records are also included to facilitate safe and effective operation and upkeep.