Komatsu WA500-1 Wheel Loader 1991– Shop Manual Set (P/N SEBM04250107)

These are separate chassis shop manuals for different serial-number series. Match the volume and its internal serial breaks to the machine before selecting component configurations, diagrams, or repair procedures.

Engine coverage: Both volumes cover machine-side S6D140-1 testing, cylinder-head work, and engine removal and installation. Full crankshaft, block, and short-block overhaul coverage requires the separate 6D140-1 Series Engine Shop Manual, which is not included.

Missing material in the 10001-up file: Printed pages 62-15–62-16 and 82-79–82-80 are absent. These gaps affect work-equipment troubleshooting cases 2–7 and early-monitor chart M-8(b).

Text Search, Bookmarks, and Wiring Detail

Search and diagram limitations: The 10001-up PDF is partly searchable; some repair pages and wiring sheets lack searchable text. The 20001-up PDF has no text search. Both have section bookmarks, although the first volume’s legacy MAIN MENU shortcut does not jump to a manual page. Small wiring labels require zooming, and some codes in the 20001-up wiring overviews remain difficult to read when enlarged.

Delivered in English as a ZIP containing two printable PDFs totaling 1,725 pages. The individual counts above already include covers, contents, revision lists, preliminary service notes, the 10001-up file’s 39 blank pages, and its closing manual-revision form.

Loader Repairs, Hydraulic Testing, and EVMS Diagnosis

The selected topics below highlight the repair coverage. Tire-and-wheel checks and speedometer-module adjustment are further examples of the material included.

• Engine and cooling: Valve-clearance adjustment, injection-timing checks, compression and blow-by testing, oil-pressure and temperature checks, plus step-by-step removal and installation of engine components.

• Power train: Stall and pressure testing, troubleshooting, and step-by-step disassembly and reassembly of the torque converter, transmission, transfer, drive shafts, differentials, and final drives.

• Steering: Steering gear, pump, valve, cylinder, linkage, and center-hinge repair, supported by steering-response checks and pressure-testing procedures.

• Brakes and air system: Brake performance and disc-wear checks, bleeding, air-system diagnosis, and service of brake valves, chambers, slack adjusters, parking brakes, and spring cylinders.

• Loader hydraulics: Pressure and drift testing, main control-valve and cylinder repair, control-lever checks, bucket-positioner adjustment, and boom kick-out adjustment.

• Electrical and EVMS: Starting, stopping, preheating, transmission, and kick-down fault finding using E-series charts, M-series monitor diagnostics, connector terminal views, and wiring diagrams.

These manuals are suited to experienced service technicians with the lifting equipment and test tools required for heavy-machine repair.

Engine Auxiliaries and Cooling Components

Machine-side sections document the engine mount, radiator and oil cooler, fuel tank and piping, and engine controls. Removal and installation instructions address the cylinder head, injection pump, nozzle holders, turbocharger, water pump, air compressor, starting motor, and alternator.

Transmission Internals and Running Gear

The damper, torque converter and PTO, transmission control valve, and center support receive component-specific coverage. Transmission work extends to clutch pistons, discs, plates, sealing rings, and assembly checks, with leak tester 799-301-1500 specified in the tool lists.

Front and rear axle removal and installation procedures connect this internal drivetrain work to the machine’s running gear. D-spec distinctions in the radiator and power-train sections identify configurations that require different drawings or service data.

Pilot Controls, Loader Components, and Assembly Cautions

Pilot-control terminology differs between the volumes: POC in the 10001-up manual and PPC in the 20001-up manual. Hydraulic-tank, hydraulic- and switch-pump, lift- and dump-cylinder, bucket-linkage, work-equipment, and counterweight procedures include assembly-specific lifting and refitting notes.

The 10001-up volume also contains a separate SA-series gear-pump section with bench delivery tests, internal disassembly and assembly, and repair limits. Steering-cylinder and brake assembly instructions address rod-surface protection and seal-lip orientation.

Center-hinge cautions address clearance-matched bearing/spacer sets and crooked bearing installation, which can damage the bearing and its fitted surface. SA-series pump notes identify reversed suction/delivery side plates and displaced seal or backup rings as potential causes of sealing-edge damage and leakage.

Circuit Drawings and Fault Isolation

The Hydraulic Circuit Diagram for Power Train, Steering Circuit Diagram, and Brake and Air Circuit Diagram show the relationships between the relevant pumps, valves, and actuators. The Hydraulic Circuit Diagram for Work Equipment, Engine Starting and Stop Circuit System Diagram, and EVMS connector-terminal/location views support tracing faults through the corresponding diagnostic charts.

Separate electrical circuits cover intermittent wipers, the air gauge, and parking-brake control.

Cab Work, Special Tools, and Workshop References

Cab removal, air-conditioner-unit service, and compressor procedures are included, with separate DAIKIN and DENSO compressor coverage in the 10001-up volume.

Heavy-component procedures provide weights, lifting points, sling guidance, and hoist-planning information. Named tools include hydraulic tester 799-101-5000, flow-meter kit 790-303-1001, and center-hinge puller 790-101-2102.

Component-specific torque tables, fluid capacities, standard and permissible values, pressure-test data, clearances, wear limits, sensor checks, and adjustment specifications accompany the repair sections.

Follow the manual’s precautions for securing the articulated frame and work equipment, releasing hydraulic and air pressure, isolating the battery, blocking the wheels, and lifting heavy assemblies.

Examples of Valve-Clearance and Brake-Wear Data

The S6D140-1 valve-clearance instructions specify 0.43 mm for the intake and 0.80 mm for the exhaust, measured cold between the crosshead and rocker lever.

For the brake-disc wear check, the 10001-up volume gives a maximum calculated piston stroke of 6.3 mm; the 20001-up volume specifies 8.0 mm. Both checks require coolant temperature and air pressure within their operating ranges.