This Service Shop Repair Manual covers the Komatsu Hydraulic Excavator models PC300-6, PC300LC-6, PC350-6, and PC350LC-6, with serial numbers PC300-6 and PC300LC-6 starting from 33001, and PC350-6 and PC350LC-6 starting from 12001. These excavators are engineered for demanding work, featuring robust construction and reliable performance for various construction and earthmoving applications. The diesel-powered SAA6D108-2 engine provides the necessary power for efficient operation. This comprehensive 809-page English language manual is designed to assist owners, mechanics, and technicians in maintaining and repairing these machines. It includes detailed information on general aspects, structure and function, testing and adjusting, disassembly and assembly, maintenance standards, and other essential topics. With actual real photo illustrations, diagrams, and schemes, the manual provides step-by-step guidance for repair, servicing, technical maintenance, and troubleshooting procedures, ensuring the longevity and optimal performance of your equipment.