2003 Komatsu PC400-7, PC400LC-7, PC450-7, PC450LC-7 Shop Manual Extract (P/N SEBM033000)

Komatsu shop manual SEBM033000, printed October 2003, covers 2003–2007 PC400-7, PC400LC-7, PC450-7, and PC450LC-7 excavators, including fixed and variable gauge specifications.

This 216-page PDF contains the General and Structure, Function and Maintenance Standard sections. Testing and Adjusting and Disassembly and Assembly are not included. The file is partly searchable.

• Power train and undercarriage: Final drive and swing machinery section views, track frames, recoil springs, idlers, carrier rollers, and track wear standards.

• CLSS hydraulics: Pump operation, LS and PC controls, main control valve sections, travel and swing motor brake functions, and relief-pressure specifications.

• Work equipment: Boom, arm, and bucket cylinder dimensions, pin and bushing clearances, hydraulic drift prevention valves, and holding-valve operation.

• Engine and electrical controls: SAA6D125E-3 installation details, engine and pump controller pin assignments, sensor characteristics, and control-system diagrams.

• Monitor functions: Attachment-flow selection for equipped multi-monitor machines, maintenance-timer resets, LCD checks, and user, service, and failure-code display.

• Service specifications: Component weights, fuel and lubricant tables, fluid capacities, and track shoe bolt torque and tightening-angle data.

This volume is suited to mechanics familiar with excavator hydraulic circuits and component measurement who need technical reference data for repair assessment.

CLSS Hydraulics and Attachment Circuits

The hydraulic sections explain pump discharge control through the LS, PC, and EPC valves, with performance curves and pressure-compensation diagrams. The Hydraulic Piping Drawing identifies connections between the pump, main control valve, cylinders, pilot controls, and center swivel joint.

Main control valve coverage separates the boom, arm, bucket, swing, and travel circuits. It also describes the boom drift prevention valve, optional arm drift prevention valve, quick return valve, and boom/arm holding valves.

The attachment circuit selector valve section distinguishes breaker return flow directly to the tank from the return path used by other attachments. Travel and swing motor sections explain brake release, safety-valve operation, and swing reversal prevention.

Motor specifications include displacement, brake-release pressure, and safety-valve settings. The travel-motor safety-valve description shows why loss of pressure relief during stopping can damage the motor or piping.

Mechanical Inspection and Engine Coverage

Final Drive and Swing Machinery section views are paired with planetary-gear backlash limits and component-specific remedies. These tables help a shop judge whether measured wear calls for repair or replacement.

Undercarriage coverage includes sprocket wear, track link pitch, pin and bushing fits, roller wear limits, and recoil spring standards. Fixed and variable gauge dimensions and model-specific weight tables support identification and handling of the correct configuration.

Boom, arm, and bucket cylinder data include stroke lengths and pin distances. Separate work-equipment tables cover connecting-pin clearances, bucket shim clearances, and arm and bucket dimensions.

Engine-related pages show the SAA6D125E-3 mounting and wet damper assembly, alongside radiator, oil cooler, and aftercooler arrangements. Detailed engine repair is covered by the separate 125-3 Series Engine Shop Manual, which is not included. Air-conditioning coverage here is limited to the component and piping layout.

Follow factory precautions when working with pressurized hydraulics or lifting heavy excavator components.

Electrical Controls and Monitor Procedures

The Total System Diagram connects the engine controller, pump controller, monitor panel, sensors, and solenoid circuits. Connector pin tables identify controller inputs and outputs; supporting sections explain auto-deceleration, overheat prevention, swing locking, and travel-speed control.

Monitor procedures cover attachment-flow selection, maintenance-status checks and timer resets, display adjustment, and LCD checking. Attachment-flow adjustment requires the multi-monitor specification, genuine attachment piping, and the attachment-installed setting.

The code-display instructions explain access to user, service, and failure codes; a full fault-code troubleshooting chapter is not included.

Circuit-diagram coverage: Functional hydraulic and electrical diagrams appear within the system sections. Chapter 90 contains only its contents page: the listed full hydraulic circuit sheets, five-part electrical circuit diagram, and air-conditioner electrical circuit are not included.

File Format and Readability

The total includes one cover/title page, four contents pages, and 11 blank pages. No separate supplement is included.

Text search: Main text and many tables are searchable, but some diagram labels and the lubricant chart cannot be searched.

Navigation: Embedded PDF bookmarks provide access to the included systems and components.

Diagram detail: Small labels in the dense system diagrams are best read with magnification.