Komatsu WB140-2N / WB150-2N Backhoe Loader Shop Manual, 2003 (P/N CEBM009802)

Komatsu’s May 2003 chassis Shop Manual, P/N CEBM009802, covers WB140-2N machines from serial A20001 and WB150-2N machines from serial A60001. It combines system explanations, testing and adjustment procedures, troubleshooting charts, and chassis repair instructions.

Text Search, Bookmarks and Circuit Sheets

Search and drawing detail: Text search is available throughout the main service sections, although labels within some hydraulic drawings are not searchable. Embedded bookmarks navigate the sections and many individual procedures. Small wiring and hydraulic-circuit labels require zooming.

Supplied as one printable, English-language 406-page PDF, including 26 pages of front matter, one revision-proposal form, and 13 blank or header-only pages.

Drivetrain, CLSS Hydraulics and Backhoe Repair

These selected workshop topics outline the main coverage. Further procedures include starter and alternator replacement, plus radiator and oil-cooler removal.

• Power-train service: Step-by-step transmission and torque-converter removal and installation, converter-pressure checks, clutch-engagement pressure tests, and operational clutch testing.

• Axles and brakes: Front and rear axle disassembly, planetary and wheel-hub service, differential carrier setup, ring-and-pinion assembly, bearing preload, backlash checks, and brake-control repair.

• CLSS hydraulics: Main and secondary relief testing, load-sensing and unloading-valve adjustment, priority-valve checks, steering-pressure testing, brake-circuit leak checks, and pump-delivery reference charts.

• Loader and backhoe assemblies: Work-equipment removal and installation, hydraulic-cylinder disassembly and reassembly, telescopic-arm service, and hydraulic-drift diagnosis.

• Engine checks: Engine-speed measurement, valve-clearance adjustment, compression testing, injection-timing checks, drive-belt adjustment, and engine/transmission assembly removal.

• Electrical documentation: Main wiring and air-conditioning schematics, component legends, connector identifiers, and wire-color codes support circuit tracing.

• Cab and climate systems: Cab, heater and air-conditioning unit removal, refrigerant recovery instructions, and pressure/temperature charts for air-conditioning fault diagnosis.

Written for service-workshop personnel, this manual is suited to trained technicians or experienced mechanics equipped for hydraulic testing, heavy-component handling, and axle setup.

Engine Applications and Overhaul Limits

Engine reference tables distinguish the naturally aspirated WB140-2N with the 4D106-1FA, the turbocharged WB140-2N with the S4D106-1FH, and the WB150-2N with the S4D106-1FA.

Internal engine work requires the separate Engine Shop Manual, WEBM4D9801, which is not included. Komatsu refers cylinder-head, oil-pump, injection-pump, injector, and governor procedures to that volume. The same applies to turbocharger, water-pump, engine oil-seal, and related engine-component work.

Hydraulic Configurations and Drift Diagnosis

The hydraulic explanations trace piston-pump operation through the PC and LS valves, servo piston, and working-mode solenoid. CLSS coverage extends to unloading, pressure cut-off, LS decompression, delivery compensation, LIFD, and priority-valve functions.

The front shovel uses two- or three-spool control valves. Backhoe arrangements include six-spool valves, seven-spool versions for a telescopic arm or hammer, and eight-spool versions combining the hammer and telescopic arm. These distinctions help match the machine’s configuration to the appropriate circuit and test points.

Pump-delivery charts distinguish naturally aspirated machines from the turbocharged configurations and show Economy and Power modes. Hydraulic-drift isolation tests distinguish control-valve leakage from cylinder-seal leakage before a repair approach is selected.

Axle Setup and Converter Installation

Power-train drawings explain the forward/reverse and 4WD drive sections and transmission control valve block. Named references include the Diagram of the Power Train and Hydraulic Convertor-Transmission Circuit Diagram.

Axle procedures extend to toe and steering-angle adjustment, pinion shimming, bearing preload, and gear-contact checks. Troubleshooting charts address axle noise, differential faults, transmission overheating, loss of drive, and failure to engage 4WD.

Forcing the torque converter into the transmission housing can damage the front pump; the installation section explains the seating precautions.

Work Equipment and Control Adjustments

Cylinder procedures cover loader raise and tilt, boom, arm, bucket, outrigger, swing, and telescopic-arm units. Work-equipment instructions also address the swing bracket, boom safety cylinder, inner telescopic arm, and inner-arm guides.

Cylinder assembly cautions identify seal orientation and sliding-surface protection; incorrect handling can damage replacement seals and cylinder surfaces.

Chassis adjustments include the return-to-dig sensor, accelerator controls, brake pedals, and microswitches. Reference tables provide control-travel data, brake and steering performance criteria, and cylinder-condition limits. Fuel and hydraulic tank removal and installation are also covered.

Circuit Drawings and Workshop Tools

Separate Hydraulic Circuit (WB140-2N) and Hydraulic Circuit (WB150-2N) sheets accompany the main Electrical Schematic and Air Conditioner Circuit. Workshop references include standard torque charts, coating-material data, wire codes, and component inspection limits.

Tool tables identify the ATR201490 air-bleeding tank cap and ATR200620 / 960119000 cylinder service attachment. Axle setup references include the CA715023 front-axle false pinion and CA715128 rear-axle false pinion.

Raised loader or backhoe equipment must be securely supported and residual hydraulic pressure released before service. Refrigerant work requires recovery equipment, and heavy assemblies require correctly rated lifting gear.

Examples of Fuel and Hydraulic Tank Refill Data

The fuel-tank installation section lists a maximum refill of 130 liters (34 gal), alongside fuel-circuit bleeding instructions.

For the hydraulic oil tank, the listed maximum refill is 92 liters (24 gal). The associated installation instructions cover circuit bleeding and the oil-level check.