This comprehensive service and repair manual provides detailed technical information for Komatsu's PC300-7EO, PC300LC-7EO, PC350-7EO, and PC350LC-7EO hydraulic excavators. It is an essential resource for technicians, mechanics, and operators seeking to perform maintenance, diagnose problems, and repair these machines. The manual covers a wide range of topics, including: * **General specifications and technical data:** This section provides an overview of the excavator's design, dimensions, and performance characteristics. * **Component descriptions:** Detailed descriptions and illustrations of all major components, including the engine, hydraulic system, undercarriage, and electrical system. * **Operating instructions:** Guidance on safe and efficient operation of the excavator, including startup procedures, operation techniques, and shutdown procedures. * **Maintenance and lubrication schedules:** Regular maintenance tasks are outlined with specific intervals and procedures for ensuring optimal performance and longevity. * **Troubleshooting and diagnostics:** Comprehensive fault code descriptions and troubleshooting guides to assist in identifying and resolving common problems. * **Disassembly and assembly procedures:** Step-by-step instructions and illustrations for disassembling, repairing, and reassembling components, ensuring accurate and efficient repair work. * **Hydraulic system diagrams and schematics:** Detailed diagrams and schematics for understanding the complex hydraulic system layout and component flow paths. * **Electrical system wiring diagrams:** Clear wiring diagrams facilitate electrical system troubleshooting and repair. * **Parts lists and diagrams:** Complete part numbers and diagrams for easy identification and ordering of replacement parts. This manual is an indispensable tool for anyone involved in the maintenance, repair, or operation of Komatsu PC300-7EO, PC300LC-7EO, PC350-7EO, and PC350LC-7EO hydraulic excavators. It provides the information needed to perform routine maintenance, troubleshoot problems effectively, and execute repairs with precision.

The Komatsu PC300-7EO, PC300LC-7EO, PC355-7EO, and PC350LC-7EO are powerful and versatile hydraulic excavators designed for a wide range of demanding construction, mining, and demolition applications. These models are known for their robust construction, high performance, and advanced technological features. The PC300-7EO and PC350-7EO are standard configurations while the PC300LC-7EO and PC350LC-7EO are long undercarriage variants, offering added stability and reach for particular tasks. All four excavators are powered by Komatsu's Tier 4 Final compliant SAA6D107E-3 engine, which delivers high torque and horsepower while meeting stringent emissions regulations. The hydraulic system is designed for precision and efficiency, featuring a variable displacement pump and sophisticated control valves for smooth operation. The Komatsu PC300-7EO and PC350-7EO series boasts a wide range of features for operator comfort and safety, including a spacious and ergonomically designed cab with climate control, a multi-function display for machine status monitoring, and an advanced safety system with safety sensors and automatic shutdown features. Additional features like optional boom and arm attachments, as well as a wide range of optional working tools, provide versatility for various applications. With their reliability, performance, and advanced technology, these excavators are a popular choice for contractors and operators seeking a durable and efficient machine for heavy-duty applications.