This manual covers the Komatsu WA120-1LC Wheel Loader, serial number 20001 and up. Engineered for demanding heavy equipment applications, this model represents a commitment to robust performance and operational efficiency. Its design prioritizes reliability and durability, ensuring consistent productivity in various work environments. The WA120-1LC is built to handle challenging tasks, offering a dependable solution for construction, material handling, and other industrial operations. This Service Repair Manual in English provides comprehensive guidance for the maintenance and repair of your Komatsu WA120-1LC. It details procedures for critical systems including the engine, power train, steering, brake and air systems, work equipment, and electrical components. The manual is designed to assist owners, technicians, and mechanics in understanding the vehicle's operation, performing routine maintenance, and executing repairs effectively, thereby maximizing the longevity and performance of the equipment.