2002 Komatsu PC400-6, PC400LC-6, PC450-6, PC450LC-6 Shop Manual

• Covers 2002 Komatsu PC400-6, PC400LC-6, PC450-6, and PC450LC-6 series excavators in both Back Hoe and Loading Shovel configurations
• Official Komatsu publication SEBM014507, published February 2002
• Details the SA6D125-2 engine platform performance, hydraulic pump operation, and swing machinery mechanics for serial numbers 32001 and 12001 and up
• Includes 47 hydraulic system diagrams, comprehensive weight distribution charts, and 16 standard torque tables for metric bolts and split flange connections

Component Structure and Technical Architecture

Mechanics need exact specifications before tearing down heavy machinery. This documentation breaks down the mechanical and hydraulic framework of the PC400-6 and PC450-6, giving you a clear view of the power train architecture. That includes the travel motors, swing circle, and final drive gear reduction ratios. It also details the functional logic of the variable displacement piston pumps, alongside TVC and LS valves and signal pressure routing. Precise schematics map out the hydraulic piping for different attachments, service valve integration, and PPC control layouts so you can trace fluid paths without second-guessing.

Technical Data and Specifications

Knowing the factory baselines is critical. Working on high-pressure heavy equipment carries inherent physical risks, so verifying exact system tolerances prior to testing or teardown is essential for shop safety. For instance, the main pump delivery pressure runs at 34.8 MPa to feed the primary 6-spool control valve assembly. Standard tightening torque for the 16 mm metric bolts is firmly set at 279 Nm.

Fluid capacities are clearly defined to ensure accurate maintenance: the hydraulic tank holds 358 liters, with 273 liters required to hit the H level mark. Engine oil pan capacity is set at 38 liters. The SA6D125-2 engine itself pushes 228 kW of flywheel power at 2,050 RPM. This documentation provides the exact hard numbers needed to verify performance drops, set up pressure gauges, or measure rebuild clearances accurately.