2002 Komatsu PC400-6, PC400LC-6, PC450-6, PC450LC-6 Excavator Shop Manual (P/N SEBM014507)

Komatsu shop manual SEBM014507, printed February 2002, covers the 2002 PC400-6, PC400LC-6, PC450-6 and PC450LC-6 excavators. It includes Back Hoe specifications and repair information, plus Loading Shovel specifications for the PC400-6 and PC400LC-6 and dedicated Loading Shovel hydraulic and electrical diagrams.

Bookmarked PDF and Diagram Detail

Search, navigation and labels: PDF text search is not available. Embedded bookmarks provide navigation to chapters, components and individual troubleshooting topics. Small wire codes, connector numbers and hydraulic diagram labels require zooming in the checked diagram pages.

Delivered as one printable 892-page PDF, including the cover, five revision-list pages and 53 blank pages. These pages are already included in the total.

Hydraulic Controls, Fault Tracing and Component Repair

These selected topics cover the main workshop sections. The manual also includes front-window auto pull-up system information and dimensional drawings of the arm and bucket.

• Hydraulic testing: Main relief pressure checks, TVC and LS valve testing, PPC output measurements, hydraulic drift diagnosis, leakage checks and air-bleeding procedures.

• Pump and valve repair: Step-by-step disassembly and assembly of the main pump, control valve, pump merge/divider valve and PPC control assemblies.

• Travel and swing: Final drive, travel motor, swing motor and swing machinery overhaul procedures, with center swivel joint service and inspection standards.

• Undercarriage and attachments: Idler, recoil spring, roller and track shoe service, plus hydraulic cylinder disassembly and work equipment removal and installation.

• Engine-related work: Compression and blow-by testing, valve-clearance and injection-timing adjustment, cylinder-head removal and installation, and engine/main-pump assembly removal.

• Electrical diagnosis: Service-code tables, monitor-panel functions, controller troubleshooting, connector pin tables and wiring diagrams for the documented equipment variants.

Written for service personnel performing workshop repairs, this manual assumes familiarity with mechanical service work and access to the specified measuring instruments, lifting equipment and special tools.

CLSS Operation and Hydraulic Fault Isolation

Component drawings explain the power train, final drive reduction gearing, variable-displacement pumps and swing machinery. Hydraulic piping drawings connect service-valve integration and PPC control layouts with the circuits being tested, so a workshop can trace fluid paths and relate operating symptoms to the relevant components.

The CLSS section explains TVC and LS control, signal-pressure routing and pump discharge characteristics. Testing and troubleshooting charts distinguish control-pressure, servo and pump problems rather than treating every slow-operation complaint as a failed main pump. Separate leakage tests help distinguish cylinder leakage from control-valve faults when work equipment drifts.

Work on these hydraulic systems requires the pressure-release, raised-equipment support and lifting precautions described in the manual.

Rebuild Procedures and Inspection Standards

The component repair sections extend beyond removal instructions. Final drive assembly includes bearing and end-play checks; travel and swing motor procedures address internal assembly and adjustment. Maintenance Standard tables provide component dimensions, clearances, spring data and repair limits, including separate hydraulic-cylinder data for Back Hoe and Loading Shovel equipment.

Serial-specific center swivel joint procedures distinguish the documented designs. Special-tool lists identify equipment such as bearing push tool 796T-626-1110, and dimensioned sketches support local manufacture of designated tools.

The main-pump assembly notes warn that impact on the valve plate can damage its sliding surface or distort it. Center swivel joint assembly instructions also identify the slipper seal and O-ring as vulnerable to installation damage.

Controller, Monitor and Wiring Diagnosis

The Actual Electric Wiring Diagram shows component locations, while the Connector Arrangement Diagram and connector pin-number tables support harness checks. The Electrical Circuit Diagram for C Mode accompanies pump-controller fault diagnosis, including TVC, LS-EPC and pressure-sensor circuits.

Dedicated Hydraulic Circuit Diagrams for Back Hoe and Loading Shovel show the different hydraulic arrangements. Electrical drawings distinguish power-window equipment, later Back Hoe machines without power windows and the documented Loading Shovel configuration. Air conditioner layouts and component removal procedures are also included.

Engine Service and Coverage Limits

Engine-related sections cover speed and oil-pressure measurement, boost-pressure checks, fuel-system adjustment and removal of components such as the injection pump, turbocharger and cylinder head. The cover directs detailed engine work to the separate 125-2 Series Engine Shop Manual, which is not included in this download.

Examples of Tank Capacities and Fastener Torques

The hydraulic-tank section lists a capacity of 358 L and an oil quantity of 273 L at the H level. These are tank figures; the lubricant chart separately distinguishes system capacity from routine refill quantities.

The engine oil-pan chart lists 38 L specified capacity, increasing to 41 L when a bypass filter is installed.

For the fastener types shown in the standard metric bolt table, a 16 mm thread is listed at 279 ± 30 Nm where no special component-specific torque applies.