The Komatsu PC400-7 PC450-7 Hydraulic Excavator Factory Service Repair Manual is a comprehensive guide designed to assist owners and technicians in maintaining and repairing these powerful machines. It provides detailed information covering a wide range of topics, making it an indispensable resource for anyone working with these excavators.

The manual begins with a comprehensive overview of general specifications, including weight tables, fuel requirements, coolant information, and recommended lubricants for the PC400-7 and PC450-7 models. It then delves into the structure and function of the excavators, covering critical components like the engine control system, power train system, hydraulic piping and circuits, main clutch, transmission, steering system, brake system, final drive, and track frame.

The manual then provides step-by-step procedures for testing and adjusting various components, including engine speed, exhaust color, valve clearance, compression pressure, blow-by, injection timing, fuel circuit, engine oil pressure, fan belt tension, fuel control linkage, power train oil pressure, and hydraulic cylinder circuits.

For more in-depth repairs, the manual offers detailed disassembly and assembly instructions for components like the starting motor, alternator, fuel injection pump, water pump, thermostat, nozzle holder, cylinder head, radiator, engine, damper, main clutch, transmission, steering pump, modulating valve, selector valve, main relief valve, steering PPC valve, steering clutch, bevel gear shaft, final drive, track frame, idler, carrier roller, track roller, track shoe, hydraulic pump, hydraulic control valve, and hydraulic cylinders.

The manual also includes a comprehensive section on maintenance standards, covering components such as the main clutch, transmission, damper, universal joint, hydroshift transmission, transmission control valve, steering pump, steering main relief valve, PPC valve, steering cylinder, bevel gear shaft, steering clutch, steering brake, final drive, track frame, idler, track roller, carrier roller, rubber crawler, hydraulic pump, hydraulic control valve, hydraulic cylinder, straight tiltdozer, power angle and tiltdozer, bucket, and link.

Finally, the manual concludes with a section on timing dozers and additional information, ensuring that you have access to a complete set of resources for troubleshooting and performing repairs. This manual is designed to be user-friendly, with clear instructions, detailed illustrations, and helpful diagrams, making it easy for anyone, from seasoned mechanics to DIY enthusiasts, to understand and utilize the information provided.

The Komatsu PC400-7 and PC450-7 are heavy-duty hydraulic excavators renowned for their power, reliability, and versatility in demanding construction and mining applications. These models, introduced in the mid-2000s, are part of Komatsu's seventh generation excavator lineup, which boasts significant advancements in fuel efficiency, operator comfort, and machine durability. The PC400-7 and PC450-7 share a similar design, but differ in their operating weight and engine power output. The PC400-7, with a gross operating weight of approximately 45 tons, is powered by a 12-cylinder Komatsu SAA6D140E-3 engine, delivering a net power output of 315 horsepower. The PC450-7, on the other hand, boasts a higher operating weight of around 50 tons and is equipped with a 12-cylinder Komatsu SAA6D170E-3 engine, generating a net power output of 354 horsepower.

Both excavators are designed for demanding operations, featuring a robust undercarriage, a powerful hydraulic system, and a spacious, ergonomic cab. The PC400-7 and PC450-7 are equipped with advanced features such as Komatsu's exclusive "Komtrax" telematics system, which provides real-time machine performance data and location tracking. These excavators offer a wide range of attachments, allowing them to handle various tasks like digging, loading, demolition, and material handling. The PC400-7 and PC450-7 are popular choices for construction projects, mining operations, infrastructure development, and other heavy-duty applications, thanks to their impressive performance, reliability, and operator comfort. Their robust construction and sophisticated technology make them valuable assets in demanding environments, contributing significantly to a wide range of projects worldwide.