This manual covers the Yanmar 4HAL and 6HAL industrial diesel engines, designed for robust performance in industrial machinery applications. These engines are engineered for reliability and efficiency, featuring a water-cooled system, fuel injection, and a present emission and engine control system. Their construction prioritizes durability for demanding operational environments. This service repair manual provides comprehensive guidance for the maintenance and repair of your Yanmar engine. It includes detailed information on scheduled maintenance, fluid specifications, electrical system service, cooling, fuel, engine, transmission, brakes, suspension, steering, and HVAC systems. Technical specifications, wiring diagrams, and maintenance checklists are also included to assist owners, mechanics, and technicians in ensuring optimal performance and longevity of the equipment.