Komatsu PC228US-2 & PC228USLC-1/-2 Excavator Shop Manual, 2003 (P/N SEBM015903)

Komatsu's May 2003 chassis shop manual, P/N SEBM015903, covers PC228USLC-1, serial 11001 and up, and PC228US-2 / PC228USLC-2, serial 15001 and up.

PDF Search, Bookmarks and Diagram Detail

Search and schematic detail: Text search is available in selected sections; most technical pages have no searchable text. Embedded PDF bookmarks provide chapter and procedure navigation. Small schematic labels require zooming, and some densely packed connector markings remain difficult to distinguish.

One printable English PDF contains 661 pages, including 26 preliminary pages with the cover, contents, revision lists, safety notices, and general workshop references. Revised and inserted technical sections are included in that total.

Hydraulic, Travel-Drive and Electrical Workshop Coverage

This content selection highlights workshop procedures and reference material. Additional topics include push-pull hydraulic couplers and coating materials.

• Hydraulic systems: HPV95+95 pump and main control valve operation, PC/LS/EPC and PPC pressure testing, hydraulic drift isolation, and air-bleeding procedures.

• Engine checks: Compression, blow-by, oil-pressure and injection-timing checks, valve-clearance adjustment, and engine-component removal and installation.

• Travel and swing: Final-drive disassembly and assembly, GM38VL travel-motor rebuilding, swing machinery service, center swivel joint repair, and motor-leakage tests.

• Undercarriage and work equipment: Track-tension adjustment, sprocket-wear checks, swing-circle clearance measurement, cylinder repair, and boom/arm assembly removal and installation.

• Electrical diagnosis: Controller and machine-monitor troubleshooting, self-diagnostic error codes, connector locations, pin tables, electrical reset procedures, and operational checks.

• Circuit diagrams: Separate full-machine hydraulic and electrical schematics for the covered machine configurations, plus controller, engine-start and machine-monitor circuit drawings.

This factory chassis shop manual is written for service personnel carrying out workshop repairs. Its procedures assume experience with heavy-component lifting, hydraulic pressure testing, electrical measurements, and special service tools.

Configuration Differences That Matter

The model tables identify the S6D102E-1-A engine in the PC228USLC-1 and the S6D102E-1-F in both -2 machines. Separate dimensions, undercarriage data, component weights, fluid specifications, and judgment standards help a shop select the correct information before repair work begins.

The PC228USLC-1 uses the KMF90AEL-3 swing motor and GM38VL travel motors. The PC228US-2 changes to the KMF90ABE-3 swing motor but retains GM38VL travel motors; the PC228USLC-2 pairs the KMF90ABE-3 with HMV110-2 travel motors.

Engine Component Work and Coverage Limits

Engine-installed procedures cover the starter, alternator, oil cooler core, fuel-injection pump, water pump, nozzle holder, turbocharger, and thermostat. Other jobs include cylinder-head removal and installation, front and rear seal replacement, and removal of the combined engine/main-pump group.

The cover directs detailed engine service to the separate 102 Series Engine Shop Manual, which is not included. Komatsu's foreword explains that complete model-wide repair coverage may also require the separate engine, electrical, and attachment volumes.

Travel-Motor Rebuilding and Chassis Repair

The GM38VL travel-motor chapter includes step-by-step disassembly and assembly procedures for the brake valve, hydraulic motor, and reduction gear. Assembly drawings, parts and tool lists, worn-part standards, hold-flange and distance-piece selection, clearance adjustment, and a final performance test support the rebuild.

Travel-motor scope: HMV110-2 coverage provides structure/function and maintenance data; the detailed internal teardown and rebuild chapter is labeled GM38VL. Match the installed motor type before selecting overhaul procedures or parts.

Other chassis procedures cover main-pump and control-valve removal, PPC valve service, recoil springs, idlers and rollers. Illustrated removal and installation pages also address the cooling pack, cab, floor frame, controller, monitor, and air-conditioning hardware.

Work Equipment and Configuration-Specific Resetting

Dedicated sections address the offset cylinder and PPC valve, interference-prevention solenoid, offset bracket, first and second boom assemblies, and service-valve circuits.

Procedure applicability: Selected arm, combined bucket/arm, and boom procedures carry PC228UU or PC228US serial labels. The counterweight mounting table separately identifies PC228UU-1 and PC228US-1 serial breaks. Match these individual sections to their printed model and serial references.

Electrical resetting varies with equipment configuration. The manual covers potentiometer, automatic-stop and depth-display checks; monoboom and tunnel machines use only the first two reset stages.

Diagrams and Fault Isolation

Separate PC228USLC-1 and PC228US-2/PC228USLC-2 hydraulic circuits are accompanied by matching electrical circuits. Controller-system, engine start/preheat/stop, and machine-monitor schematics provide more focused electrical references.

Troubleshooting is organized into S-mode engine, E-mode controller/electrical, F-mode input-signal, H-mode hydraulic/mechanical, and M-mode machine-monitor sections. H-mode charts address slow operation, low power, drift, travel, swing, pump noise, and compound-operation complaints.

Connector arrangement drawings and pin tables link electrical measurements to the diagnostic charts. Input-signal checks help distinguish electrical faults from hydraulic or mechanical complaints even when no error code is displayed.

Special Tools, Inspection Standards and Shop Cautions

Komatsu's special-tool list connects part numbers to specific jobs. Examples include the 790-331-1110 cylinder-head wrench, 795-799-1390 injection-pump puller, 790-101-2501 center-swivel push-puller, and 790-502-1003 hydraulic-cylinder repair stand. Dimensioned sketches also document locally manufactured special tools.

Maintenance standards cover fits, backlash, end play, spring criteria, wear limits, and work-equipment pin/bushing clearances. Torque tables, fluid data, hydraulic test specifications, and electrical values accompany the relevant work.

Component cautions: The injection-pump procedure warns that continued engine barring after the TDC positioning pin engages can break the pin. Hydraulic precautions address pump seizure from inadequate air bleeding and piston-packing damage from premature full-stroke cylinder operation.

Before hydraulic or heavy-component repair, follow the manual's pressure-release, blocking, hoisting, and electrical-isolation precautions.

Selected GM38VL Wear and Clearance Data

For GM38VL travel-motor inspection, the piston-to-shoe axial clearance is listed as 0.05 mm standard, with an allowable value of 0.15 mm.

The rear-flange-to-spool diametral clearance is 10–20 µm standard, with an allowable value of 25 µm. These examples come from the travel-motor worn-part inspection tables and distinguish standard dimensions from allowable wear criteria.