The Komatsu PC138USLC-2EO is a robust excavator designed for demanding construction and industrial applications. Featuring a powerful Komatsu SAA4D107E-2 Tier 3 certified engine with 98 HP and 4.5 liters of displacement, this machine delivers exceptional performance. Its hydrostatic transmission, coupled with a compact design and an operating weight of 13,620 kg, ensures maneuverability and efficiency on various job sites. The PC138USLC-2EO is engineered for reliability and productivity, offering impressive digging capabilities with a maximum depth of 5,750 mm and a reach of 8,445 mm. This Workshop Service Repair Manual provides comprehensive guidance for the Komatsu PC138USLC-2EO. It covers essential maintenance procedures, detailed troubleshooting steps, and critical technical specifications, including engine oil capacity, hydraulic oil capacity, and coolant capacity. This manual is an indispensable resource for owners, mechanics, and technicians, enabling them to perform routine servicing, diagnose issues, and ensure the optimal performance and longevity of their equipment. The English-language document is designed to facilitate effective repair and maintenance operations.