2005 Hitachi Zaxis 330 / 330LC / 350H / 350LCH / 370MTH Excavator Workshop Manual (P/N W1HH-E-01)

This 2005 Hitachi Workshop Manual, Vol. W1HH-E-01 (Manual No. KM-1HH-E), covers Zaxis 330, 330LC, 350H, 350LCH, and 370MTH hydraulic excavators. Its repair coverage extends from upperstructure and undercarriage assemblies to the engine and accessories.

• Upperstructure: Cab, counterweight, and main-frame removal and installation, plus swing-device, swing-motor, and parking-brake release-valve service.

• Hydraulic pumps: Pump-device, main-pump, regulator, and pilot-pump disassembly and reassembly, supported by component inspection standards.

• Valves and controls: Control-valve, pilot-valve, pilot shut-off, shockless-valve, and proportional-solenoid service, with internal assembly drawings.

• Undercarriage: Travel-device, travel-motor, and brake-valve overhaul, plus swing-bearing, center-joint, track-adjuster, front-idler, roller, and track service.

• Front attachment: Boom, arm, and bucket cylinder removal, seal arrangements, disassembly, reassembly, and rod inspection, with attachment connection dimensions.

• Engine repair: Internal engine inspection and overhaul, fuel-injection service and calibration data, cooling, lubrication, and turbocharger troubleshooting.

• Starting and charging: Alternator and starter-motor disassembly, electrical component checks, charging-circuit diagrams, and alternator bench-testing procedures.

The manual is written for experienced technicians and calls for appropriate lifting equipment, measuring instruments, and specialty service tools.

Workshop Scope and Hydraulic Assemblies

This download contains the workshop volume. The separate Operational Principle and machine Troubleshooting volumes are outside this file; engine troubleshooting is included in Section 5.

Main-pump maintenance tables distinguish spline wear, plunger clearances, and valve-plate flatness. Control-valve drawings identify internal spools, check valves, and relief valves. Proportional-solenoid sections distinguish SC, SI, SG, torque-control, and maximum pump 2 flow-rate limit valves.

The pump instructions warn that trapped air in the housing can damage the pump at startup. Following the factory precautions for residual hydraulic pressure, attachment support, and heavy component lifting is critical during service.

Travel Assemblies and Undercarriage Differences

Travel-device coverage separates early and later assemblies for the 330/330LC/350H/350LCH and provides dedicated 370MTH procedures. Exploded reduction-gear views accompany travel-motor and brake-valve assembly information.

Separate 370MTH track-adjuster procedures specify spring tooling ST 4932. Upper rollers are replaced as assemblies; lower rollers have internal disassembly and reassembly instructions. The floating-seal precautions explain how twisted or unevenly seated O-rings can cause leakage or seal damage.

Cylinder Construction and Attachment Fit

Early and later cylinder drawings show different internal seal and retaining arrangements. These drawings help identify the installed construction before replacement seals or internal parts are selected.

The Standard Dimensions for Arm and Bucket Connection and Standard Dimensions for Arm and Boom Connection drawings document attachment interfaces. Related maintenance tables cover pin, bushing, and attachment wear.

Engine, Fuel System, and Electrical Repair

The Isuzu engine section covers cylinder-head disassembly, valve guides and seats, camshaft and timing gears, pistons, crankshaft, cylinder liners, and cylinder-block inspection. Cooling and lubrication chapters add thermostat, water-pump, oil-pump, and oil-cooler procedures.

Fuel-system coverage includes injection timing, nozzle opening-pressure and spray checks, and injection-pump calibration. Calibration tables identify Isuzu pump assembly 1-15603-334-1 / Zexel 106671-6451 and include an Injection Volume and Governor Performance Diagram.

Starting and charging chapters cover brushless-alternator and geared-starter repair, electrical tests, a Charging Circuit schematic, and alternator bench-test connections. Engine and turbocharger troubleshooting tables address starting, smoke, output, overheating, and charging faults.

Factory Specifications and Service Tools

T-, H-, and M-grade bolt torque charts are supplemented by hydraulic hose and piping-joint specifications, component maintenance standards, and factory painting color codes. Tool references include pump workbench ST 5050 and compression-gauge adapter 5-8840-2622-0.

A Preview of Pump Backlash and Engine Check Data

A few examples show the inspection and adjustment data included in the manual. Pump-device gear backlash is listed at a standard 0.48 mm, with an allowable limit of 1.5 mm.

For the covered 6HK1XQA engine, intake and exhaust valve clearance is 0.40 mm cold. Compression data lists a standard 3.24 MPa and a service limit of 2.26 MPa, measured with coolant at 20°C and cranking speed around 200 rpm.

Searchable Sections, Bookmarks, and PDF Contents

Text search and diagram detail: Machine-service sections contain searchable text, while the Engine and Accessory pages, PDF pp. 519–748, do not. Embedded bookmarks provide section and procedure navigation, including the engine chapters. Small charging-circuit and bench-test labels are readable when enlarged, though some fine circuit lines are faint.

Supplied as one printable, English-language PDF with 752 pages. That total already includes the cover, 29 blank pages, 13 memo pages, and one service-manual revision-request form.