This manual covers the Komatsu WA120-3MC Wheel Loader, a robust and reliable machine designed for demanding construction and material handling applications. Known for its efficient operation and durable construction, the WA120-3MC is engineered to provide consistent performance in various work environments. Its design prioritizes operator comfort and safety, featuring a standard ROPS/FOPS cab, and it is built to deliver exceptional productivity through its powerful engine and versatile capabilities. This model represents a commitment to quality and operational excellence in the heavy equipment sector. This comprehensive Service and Operating Manual provides essential information for the maintenance, repair, and operation of the Komatsu WA120-3MC Wheel Loader. It details critical procedures, technical specifications, and troubleshooting guides necessary for keeping the equipment in optimal working condition. Owners, operators, and service technicians will find detailed instructions on engine, transmission, hydraulic systems, and routine maintenance schedules. The manual is an indispensable resource for ensuring the longevity, safety, and peak performance of your WA120-3MC.