The Komatsu PC300-7, PC300LC-7, PC350-7, and PC350LC-7 excavators represent the Dash 7 generation, engineered for robust performance and reliability in demanding applications. These machines are powered by the Komatsu SAA6D114E-2 turbocharged, aftercooled, direct injection diesel engine, offering substantial horsepower for efficient operation. With advanced hydrostatic transmissions featuring electronic control and auto-shift capabilities, these excavators provide precise maneuverability and power delivery. Their substantial operating weights and impressive digging capabilities, including significant digging depth and reach, make them ideal for a wide range of construction and earthmoving tasks. This manual serves as a comprehensive guide for the operation, maintenance, and repair of the Komatsu PC300-7, PC300LC-7, PC350-7, and PC350LC-7 excavators. It details essential maintenance procedures, including fluid capacities and service intervals for engine oil and hydraulic oil filters, along with critical technical specifications for engine, transmission, and dimensions. Safety guidelines and troubleshooting information are also included to ensure optimal performance and longevity of the equipment. This resource is designed to assist owners, operators, and service technicians in effectively maintaining and repairing these powerful machines.