Hitachi EX120-3 Excavator Technical & Workshop Manual PDF Download

Hitachi EX120-3 Excavator Technical & Workshop Manual

The Hitachi EX120-3 Excavator Technical & Workshop Manual is the combined service documentation for the EX120-3 hydraulic excavator. This PDF brings together the Technical Manual (T/M) and Workshop Manual (W/M) portions into one reference for maintenance, troubleshooting, testing, repair, and overhaul. The manual covers the EX120-3 machine fitted with the ISUZU 4BD1T diesel engine, applicable to serial number 12V-40001- and up.

File Details

• Manual Type: Technical Manual and Workshop Manual
• Brand: Hitachi
• Model: EX120-3
• Engine: ISUZU 4BD1T
• Language: English
• File Format: PDF
• Page Count: 1005 pages
• Applicable Serial Number: 12V-40001-

Chapters Covered

• Group 01 – General Information: Foreword, Specifications, Working Ranges, Transportation, Shoe Types and Applications, Weight
• Group 02 – Fuels and Lubricants: Service Refill Capacities, Fuel, Greasing, Engine Oil, Gear Oil, Hydraulic System, Cooling System
• Group 03 – Interchangeability: Interchangeability of EX120-3 and EX120-2, Installation of Attachments
• Group 04 – Machine Numbers: Machine Type and Serial Number, Engine Type and Serial Number, Travel Motor, Swing Motor
• Group 05 – Components Specifications: Engine, Engine Accessories, Hydraulic Devices, Electrical Equipment
• Layout: Layout of Upprestructure
• Tank: Hydraulic Oil Tank, Fuel Tank
• Pump Device: Outline, Main Pump, Pilot Pump, Engine Speed Sensor, Pressure Sensor, Pump Displacement Angle Sensor
• Swing Device: Outline, Swing Motor, Brake Valve, Swing Parking Brake, Swing Dampener Valve, Swing Reduction Gear
• Control Valve: Outline, Unloading Valve, Main Relief Valve, Overload Relief Valve, Variable Pressure Compensated Valve, Shuttle Valve, Differential Pressure Sensor, Holding Valve
• Pilot Valve: Outline, Operation
• Others: Pilot Shut-off Valve, Shockless Valve, Accumulator, Solenoid Valve, Pump Displacement Solenoid Valves, Swing Dampener Valve, Solenoid Valve Assembly, Proportional Solenoid Valve, Directional Solenoid Valve, Reducing Valve, Pilot Relief Valve
• Undercarriage: Center Joint, Swing Bearing, Travel Device, Track Link Assembly, Lower Rollers, Upper Roller, Track Adjuster, Front Idler, Track Frame
• Electrical System: Component Location, Relays, Monitor and Switch Panel, Main Circuit (Power, Preheat, Engine Start, Charging, Surge Voltage Prevention, Accessory, Engine Stop), Control System (Engine Control, Pump and Valve Control), Monitor, Inspection and Maintenance, Fault Codes
• Hydraulic System: Hydraulic Circuit, Main Circuit, Pilot Circuit, Pump Control (Load Sensing, Speed Sensing), Valve Control (Flow Dividing), Other Controls (Travel Speed, Swing Parking Brake Release, Warm-Up, Swing Dampening, Power Boost), Control Circuit (Neutral, Combined Operation)
• Workshop Manual Portion: Maintenance and repair procedures, maintenance standards, removal/installation and disassembly/assembly procedures

What This Manual Provides

The Technical Manual portion opens with general information, working ranges, transportation data, shoe types and applications, and operating weights. It then covers fuels and lubricants – including service refill capacities, recommended fuel, greasing points, engine oil, gear oil, hydraulic oil, and cooling system specifications. Interchangeability between the EX120-3 and EX120-2 is documented, followed by machine number locations and component specifications for the engine, hydraulic devices, and electrical equipment.

The systems sections cover the layout of the upprestructure, the hydraulic oil tank and fuel tank, the pump device including the main pump and pilot pump, the swing device with its motor, brake valve, parking brake, dampener valve, and reduction gear, and the control valve with unloading, main relief, overload relief, variable pressure compensated, shuttle, differential pressure, and holding valves. The pilot valve, pilot shut-off valve, shockless valve, accumulator, and the various solenoid valves are also detailed. The undercarriage section covers the center joint, swing bearing, travel device, track components, track adjuster, front idler, and track frame.

Electrical coverage includes component location, relays, monitor and switch panel layout, and the main circuits – power, preheat, engine start, charging, surge voltage prevention, accessory, and engine stop. The control system chapter explains engine control and pump/valve control circuits, while the monitor chapter covers panel functions, gauges, indicators, and switches. Inspection and maintenance procedures, fuse testing, fusible link replacement, alternator troubleshooting, sensor installation and adjustment, connector handling, and fault code lists for the EC and PVC controllers are all included. The hydraulic system chapter explains the hydraulic circuit, main circuit, pilot circuit, pump control (load sensing and speed sensing), valve control (flow dividing), and other controls including travel speed, swing parking brake release, warm-up, swing dampening, and power boost.

The Workshop Manual portion adds the technical information needed for maintenance and repair of the machine, tools and devices needed for maintenance and repair, maintenance standards, and removal/installation and disassemble/assemble procedures.

Who This Manual Is For

This Hitachi EX120-3 technical and workshop manual suits equipment owners performing their own maintenance, independent repair shops servicing Hitachi excavators, and technicians who need OEM-level specifications and procedures on hand. The combined T/M and W/M format means troubleshooting guidance and repair instructions are in the same document, so you are not switching between separate references.

Get the Complete EX120-3 Service Reference

With the Hitachi EX120-3 Excavator Technical & Workshop Manual PDF, you have the specifications, procedures, and diagnostic information needed to keep an EX120-3 working – from routine fluid changes and track adjustment to hydraulic component repair, electrical troubleshooting, and engine service. Correct procedures and accurate specifications reduce the risk of damage, wasted time, and repeat repairs. This manual gives you the reference material to do the job properly.

Delivered instantly as a PDF download after payment. No shipping, no waiting. View it on any device, and print the pages you need for the workshop.