This Service Repair Manual covers the Komatsu WA120L-3MC Wheel Loader, serial numbers 54104 and up. Engineered for demanding applications, this robust machine embodies Komatsu's commitment to reliability and performance. Its versatile design and powerful diesel engine make it an essential asset for various construction and material handling tasks. The WA120L-3MC is built to deliver efficiency and durability, ensuring productivity across a wide range of operational environments. This comprehensive manual provides detailed information for maintaining and repairing your Komatsu WA120L-3MC. It includes essential sections covering general information, structure and function, testing and adjustment procedures, disassembly and assembly, maintenance standards, and other critical areas. Whether you are an owner, technician, or mechanic, this guide will equip you with the knowledge necessary to ensure optimal performance, longevity, and safe operation of your wheel loader.