This manual covers the Komatsu WA120-1LC Wheel Loader, serial numbers 20001 and up. Engineered for demanding tasks, this machine represents a commitment to robust construction and operational efficiency. Its design prioritizes reliability and performance, making it suitable for a wide range of industrial and construction applications where dependable material handling is essential. This comprehensive Service Repair Manual and Operation & Maintenance Manual provides detailed guidance for the Komatsu WA120-1LC. It encompasses essential information for operation, maintenance, and repair, including safety precautions, specifications, lubrication schedules, and troubleshooting procedures. The manual is designed to assist operators, technicians, and mechanics in ensuring the peak performance, economical operation, and longevity of the wheel loader through effective servicing and repair.