Komatsu D57S, WA320, WA380, WA420, PC300-5, and EG150BS-5 108 Series Diesel Engine Shop Manual, 1998 (P/N SEBE62210104)

This September 1998 Komatsu 108 Series Diesel Engine Shop Manual (P/N SEBE62210104) covers S6D108-1 and SA6D108-1 engines in D57S-1 and D57S-1B, WA320-3, WA380-3, WA420-3, PC300-5, PC300HD-5, and PC360LC-5 applications. It also provides application-specific data for generator sets, the Australian AUSTOFT sugar cane harvester, and industrial engine configurations.

PDF Bookmarks and Wiring Detail

Navigation and diagram detail: Bookmarks link to chapters and individual procedures. PDF text search is unavailable. Small terminal labels and wire codes on the EG150BS-5 schematic are legible when zoomed in.

The ZIP contains one printable English PDF with 254 pages, including the original cover and 14 blank pages.

Engine Testing, Fault Finding, and Bench Overhaul

The topics below are selected highlights. The manual also includes electrical wire-code and unit-conversion tables.

• Engine checks and injection timing: Step-by-step valve-clearance adjustment and compression testing, plus injection timing by match marks, the laminated coupling, or the delivery-valve method.

• Engine controls and performance: Fuel-cut solenoid linkage, stop-motor cable and engine-speed sensor adjustment, plus running-in standards and dynamometer test criteria.

• Fault finding: Sixteen troubleshooting topics cover hard starting, no-start conditions, poor acceleration, stalling, hunting, low power, and exhaust smoke.

• Intake, cooling, and electrical: Turbocharger section views, inlet- and outlet-control cooling diagrams, and wiring diagrams for the engine starting and charging circuits.

• Bench overhaul: Step-by-step teardown and reassembly, cylinder-head and valve work, timing gear replacement, crankshaft grinding, and rear seal replacement.

• Inspection standards: Wear limits, clearances, runout checks, tightening specifications, fluid capacities, component weights, and coating-material references.

Komatsu prepared this engine volume for service workshop technicians who diagnose, adjust, and repair diesel engines.

The overhaul procedures start with the engine mounted on a stand. For engine removal and work on the chassis, powertrain, hydraulics, brakes, steering, attachments, or machine-level electrical system, use the appropriate machine-specific documentation.

Air, Oil, Coolant, and Electrical Systems

Intake and exhaust coverage includes the air cleaner, electronic dust indicator, aftercooler, and exhaust manifold. The turbocharger drawings distinguish the Schwitzer S2B on the WA320-3 and WA380-3 from Garrett TO4E installations, including the WA420-3 wastegate and intake safety valve.

The lubrication chart shows the oil pump, filter safety valve, and oil cooler. The cooling diagrams distinguish thermostat and water-pump layouts. The dedicated EG150BS-5 schematic identifies the emergency relay, stop solenoid, oil-pressure and coolant-temperature switches, and glow-plug circuit.

Pump Calibration and Engine Diagnosis

Match the pump assembly number to the application before selecting a calibration sheet. The S6D108-1 specifications list Bosch PES-AD/RSV equipment, and the calibration sheets identify Zexel PE-AD pumps. The SA6D108-1 sheets cover Denso NB (EP-9) pumps. The fuel-system chapter also shows the nozzles, filter, pump drive case, and mechanical governor.

The nine performance curves include the Egypt EIM power unit. The EG150BS-5 and OEM generator entries include running-in, calibration, and standard-value tables. The EG185B-L-1, DENYO DCA180, and SA6D108-M-1 have separate specification or test data. For the Australian AUSTOFT, the performance-curve captions and pump calibration index use different engine-number breakpoints. Use the pump assembly number to identify the applicable calibration sheet.

The no-start charts distinguish an engine that will not crank from one that cranks with or without fuel injection. Other charts address excessive oil or fuel consumption, oil and coolant contamination, low oil pressure, overheating, noise, and vibration. The test-tool list identifies the 799-203-8000 multi-tachometer and 799-203-2002 engine-pressure measuring kit. Keep clear of rotating parts and hot exhaust components during engine testing.

Cylinder Head, Liners, and Rotating Assembly

The rebuild chapter covers the block, crankshaft, pistons and connecting rods, valve train, flywheel, and housing. The parts repair chapter shows head resurfacing and pressure testing, valve-seat insert and guide replacement, valve grinding, cam bushing replacement, crank and cam gear work, flywheel ring gear replacement, and main bearing cap machining.

The overhaul tool list includes the 790-501-2000 engine stand, 795-100-2800 piston-ring tool, 790-472-2000 liner puller, and 795-215-1711 liner driver. A replacement liner must match the block’s S/M/L grade. A tilted press fit can crack the liner, and dirt on the mating surfaces can distort it. Incorrect fuel-cut linkage can burn the solenoid coil or damage the injection-pump governor, and a stop-motor cable set with no clearance can damage the pump.

Thermostat and Injection Timing Examples

The thermostat section lists an initial opening temperature of 71 ± 2°C for the inlet-control design shown on the PC300-5 and 76.5 ± 2°C for the outlet-control design shown on the EG150BS-5.

The SA6D108-1 standard-value table lists injection timing at 15–17° BTDC for the PC300-5, PC300HD-5, and PC360LC-5 applications and 21–23° BTDC for the WA420-3.