Komatsu D57S, WA320, WA380, WA420, PC300-5, and EG150BS-5 Diesel Engine Shop Manual (P/N SEBE62210104)

• Covers the S6D108-1 and SA6D108-1 engine builds used in D57S-1/D57S-1B, WA320-3, WA380-3, PC300-5, PC300HD-5, PC360LC-5, and WA420-3 equipment. Separate specification, calibration, or performance data is provided for EG150BS-5 and OEM generators, EG185B-L-1, DENYO DCA180, the Egypt EIM power unit, SA6D108-M-1, and early/late AUSTOFT sugar cane harvester engines.
• Distinguishes hardware that changes the repair approach, including Garrett TO4E and Schwitzer S2B turbochargers, the WA420-3 wastegate and intake safety-valve arrangement, inlet-control versus outlet-control cooling systems, and the Bosch/Zexel and Denso fuel-injection configurations.
• Explains valve-clearance adjustment, compression testing, fuel-injection timing by match-mark, laminated-coupling, and delivery-valve methods, fuel-cut solenoid linkage, engine stop-motor cable adjustment, engine-speed sensor setting, running-in standards, and dynamometer performance checks.
• Tracks faults through sixteen factory troubleshooting charts covering slow cranking, no-start conditions, poor acceleration, stalling, hunting, low power, black or blue exhaust, excessive oil or fuel consumption, oil/coolant cross-contamination, low oil pressure, overheating, abnormal noise, and vibration.
• Documents complete stand-mounted teardown and rebuild work, plus cylinder-head resurfacing, valve-seat and guide replacement, head pressure testing, valve grinding, cam-bushing and gear replacement, main-bearing-cap machining, crankshaft grinding, and rear-seal replacement.
• This edition is a 254-page PDF with Komatsu publication code SEBE62210104, printed September 1998. It contains nine application-specific engine performance curves, fuel-pump calibration sheets, testing-tool and overhaul-tool lists, wiring diagrams, component section views, torque data, and maintenance-standard tables.

Engine Architecture and Systems

The structure-and-function section goes well beyond basic component identification. It follows the intake and exhaust path through the aftercooler, air cleaner, electronic dust indicator, turbocharger, and exhaust manifold, then breaks down the cylinder head, block, crankshaft, pistons, connecting rods, timing gears, valve train, flywheel, and housing. Lubrication coverage includes the system chart, oil pump, built-in filter safety valve, and oil cooler. Fuel-system material covers the injection pump, mechanical all-speed governor, nozzles, filter, pump drive case, engine stop motor, and fuel-cut solenoid. Cooling and engine electrical chapters add thermostat and water-pump variants, starting and charging circuits, glow plugs, relays, and oil-pressure switching.

The configuration details matter when parts or test procedures are selected. The S6D108-1 specification pages identify BOSCH PES-AD/RSV equipment, while the related pump-calibration sheets use ZEXEL manufacturer data. SA6D108-1 builds use the DENSO NB (EP-9)/RSV system. The manual also separates the Schwitzer S2B installation used on WA320-3/WA380-3 machines from the Garrett TO4E arrangements used elsewhere, including the wastegated WA420-3 setup.

Testing, Troubleshooting, and Repair Work

Testing and adjusting covers checks and settings used before and after repair: valve clearance, compression, injection timing, stop-system linkage, sensor position, running-in, and performance criteria. Model-specific injection-pump calibration pages identify pump assembly numbers, test parts, governor curves, and application assignments. The testing-tool list names factory equipment such as the 799-203-8000 multi-tachometer and 799-203-2002 engine-pressure measuring kit.

For bench work, the overhaul chapter assumes the engine has already been removed and secured to a stand. It covers overall disassembly and assembly with dedicated tooling such as the 790-501-2000 overhaul stand, 795-100-2800 piston-ring tool, 790-472-2000 liner puller, and 795-215-1711 liner driver. Maintenance-standard tables then supply inspection limits for the turbocharger, head, valves and guides, rocker gear, liners, block, crankshaft, camshaft, pistons and rings, connecting rods, timing gears, flywheel housing, oil pump and valves, water pump, and thermostat.

The factory cautions are specific. Incorrect fuel-cut solenoid linkage can burn the solenoid coil or bend and scuff the injection-pump governor; zero-clearance stop-motor adjustment can place damaging force on the pump. During liner repair, the S/M/L liner class must match the block marking, and a tilted or contaminated press fit can crack or distort the replacement liner.

Technical Specification Preview

The reference material is organized by application rather than treating every 108 Series build as identical. EG150BS-5 coverage includes its specification sheet, performance curve, running-in data, injection-pump calibration, standard-value table, dedicated engine wiring diagram, and charging/starting configuration. AUSTOFT coverage is also divided into early and later engine-number groups across the performance, calibration, and standard-value sections.

Useful drawings include the lubrication and fuel-system charts, inlet- and outlet-control cooling diagrams, the EG150BS-5 wiring schematic, Garrett TO4E and Schwitzer S2B section views, and injection-pump governor performance curves. The repair data is backed by component-specific tightening information, fluid-capacity and part-weight tables, wear and clearance limits, runout checks, pressure-test criteria, and coating-material references.

This is the 108 Series engine volume. It does not replace the machine-specific chassis, powertrain, hydraulic, brake, steering, attachment, or machine-level electrical manuals, and it does not cover removal of the engine from each individual machine. Its repair procedures begin with the engine on an overhaul stand.