This comprehensive repair manual provides in-depth information for the Komatsu HM300-3 Articulated Dump Truck, covering serial numbers 3001 and up. It specifically addresses the Komatsu SAA6D125E-6 engine, a 4-cycle, water-cooled, in-line 6-cylinder, direct injection engine equipped with a turbocharger and air-cooled aftercooler. The manual features detailed exploded views and step-by-step instructions with accompanying pictures and diagrams, making it an invaluable resource for technicians and mechanics. It covers an extensive range of topics, including: * **Specification:** A detailed breakdown of the HM300-3's technical specifications. * **Structure and Function:** An overview of the truck's design and how its various components work together. * **Engine and Cooling System:** Comprehensive information on the engine, including its operation, maintenance, and troubleshooting. * **Powertrain:** In-depth coverage of the transmission, axles, and drivetrain components. * **Steering System:** Detailed instructions on the steering system, its components, and potential issues. * **Brake System:** A thorough examination of the braking system, including its operation, maintenance, and troubleshooting. * **Undercarriage and Frame:** A detailed guide to the undercarriage and frame, including maintenance and repair procedures. * **Hydraulic System:** A comprehensive section on the hydraulic system, covering its operation, maintenance, and troubleshooting. * **Cab and Attachments:** Information on the cab, its components, and various attachments. * **Electrical System:** A detailed guide to the electrical system, including wiring diagrams and troubleshooting procedures. * **Standard Value Table:** A reference table containing important specifications and values for various components. * **Testing and Adjusting:** Detailed instructions on testing and adjusting various components and systems. * **Troubleshooting:** A comprehensive section dedicated to diagnosing and solving common problems. * **Disassembly and Assembly:** Step-by-step instructions for dismantling and reassembling various components. * **Maintenance:** A detailed guide on routine maintenance procedures, ensuring optimal performance and longevity of the HM300-3.

The Komatsu HM300-3 Articulated Dump Truck is a powerful and versatile machine designed for heavy-duty hauling applications in various industries, including mining, construction, and quarrying. This robust truck boasts a maximum payload capacity of 30 metric tons (33 U.S. tons) and is powered by a reliable Komatsu engine offering exceptional torque and horsepower. The articulated design, a hallmark of Komatsu's heavy-duty dump trucks, enables exceptional maneuverability and operation in tight spaces, making it an ideal choice for challenging terrain and tight job sites. The HM300-3 is equipped with a spacious and comfortable cab offering excellent visibility and operator ergonomics, ensuring a safe and productive working environment. The HM300-3 is engineered for durability and long service life, featuring a robust frame, axles, and suspension system designed to withstand demanding working conditions. Its advanced hydraulic system provides smooth and efficient operation of the dump body and other components. Furthermore, the HM300-3 is equipped with a range of safety features, including an emergency braking system, a rollover protection structure (ROPS), and a fall protection system ensuring worker safety. Komatsu's commitment to environmental responsibility is evident in the HM300-3, which incorporates fuel-efficient technologies and low-emission engine design to minimize environmental impact. The HM300-3 is renowned for its reliability, high productivity, and low operating costs, making it a popular choice for businesses seeking a powerful and dependable hauling solution.