The Komatsu WA120-3MC Avance Plus is a robust wheel loader designed for demanding operational environments. Featuring a powerful Komatsu S4D102E-1 diesel engine with a displacement of 3.9 L, it delivers 75 kW of gross power and 68 kW of net power. Its transmission is a 4-speed forward and 4-speed reverse Powershift type, contributing to efficient material handling. With a rated bucket capacity of 1.2 m³ and an operating weight of 8500 kg, this machine is engineered for reliability and performance in various construction and material handling applications. This Service Manual and Operation & Maintenance Manual provides comprehensive guidance for the Komatsu WA120-3MC Avance Plus, covering serial numbers A31001 and up. It details essential maintenance procedures, including capacities for engine oil (11 L), hydraulic system oil (57 L), coolant (18 L), and fuel (130 L). The manual also encompasses technical specifications, troubleshooting information, and safety guidelines. Its purpose is to assist owners, mechanics, and technicians in effectively maintaining and repairing the equipment, ensuring optimal performance and longevity.