Part of the Hitachi Repair Manuals.
Wrenching on a Hitachi EX400–EX450 series excavator? This 914-page Hitachi EX400–EX450 Series Service Manual PDF covers the EX400-3, EX400-3C, EX400LC-3, EX400LC-3C, EX400H-3, EX450H-3C, EX400LCH-3, and EX400LCH-3C hydraulic excavators. Inside: full electrical circuit diagrams with connector terminal positions, hydraulic schematics with circuit operation walkthroughs, a heavy troubleshooting section with harness checks, and step-by-step teardown procedures for the pump device, swing device, control valve, travel system, and front attachment. You also get operational performance test standards, so you can measure your machine against real factory numbers. Torque cap (84) to 340 N·m (253 lbf·ft), then fill the gearbox with 2.3 L of gear oil before it goes back to work. No more chasing wiring faults with a multimeter and a prayer. Bookmarked and text-searchable; jump straight to your model's circuit or find any spec by keyword.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Safety Procedures and Personal Protection | 1-8 | Safety Symbols, Emergency Preparedness, Protective Clothing, Noise Protection, Flying Debris Protection |
| Service Work Preparations | 9-20 | Machine Parking, Service Warnings, Machine Support, Travel System Maintenance, Swing System Maintenance |
| Maintenance Practices and Safety | 21-40 | Service Procedures, Work Area Cleanliness, Exhaust Fumes, Work Area Illumination, Battery Safety |
| Tool and Fluid Safety | 41-60 | Tool Usage, Moving Parts Safety, High-Pressure Fluids, Fire Prevention, Battery Handling |
| Welding, Lifting, and Disposal | 61-80 | Cooling System Service, Welding Safety, Heating Near Fluid Lines, Lifting Equipment, Fluid Disposal |
| Safety Signs and Machine Return | 81 | Safety Sign Maintenance, Machine Return Procedures, Handholds and Steps, Machine Operation Precautions |
| General Infomation | 9-20 | Precautions for Disassembling, Assembling, Tightening Torque, Torque Chart |
| Uppersturucture | 21-176 | Cab, Counterweight, Main Frame, Pump Device, Control Valve, Swing Device |
| Undercarriage | 177-292 | Swing Bearing, Travel Device, Center Joint, Track Adjuster, Front Idler, Roller |
| Front Attachment | 293-330 | Cylinder, Boom, Arm, Bucket |
| Special Tools | 331-338 | Special Tool List |
| Engine and Accessories | 339-522 | Engine Assembly, Lubricating System, Cooling System, Fuel System, Turbo Charger, Air Compressor |
| Specification | 531-562 | General Information, Fuels and Lubricants, Interchangeability, Machine Numbers, Component Specifications |
| Upperstructure | 563-626 | Outline, Tanks, Pump Device, Swing Device, Control Valve, Pilot Valve |
| Electrical System | 649-710 | Component Location, Control System, Monitor, Circuit Operation, Inspection and Maintenance |
| Hydraulic System | 711-736 | General, Control System, Circuit Operation |
| Operational Performance Test | 737-790 | Performance Test, Engine Test, Excavator Test, Hydraulic Component Test, Standard |
| Troubleshooting | 791-910 | Diagnosing Procedure, Connector, Troubleshooting a, Troubleshooting B, Troubleshooting C, Harness Check |
| Ex400-3 Electrical Circuit | 911 | Serial No. 5001 and Up (Issue 9601), Key Switch and Starter Circuit, Monitor Controller, Relays and Fusible Links, Pump and Control Valve Solenoids |
| Ex400-3 Electrical Circuit (Connector) | 912 | Serial No. 5001 and Up, Table of Connector Terminal Positions, Premated and Di-Cek Connectors, Wiper Relay Wiring |
| Ex400-3C Electrical Circuit | 913 | Serial No. 6001 and Up, Key Switch and Starter Circuit, Monitor Controller, Relays and Fusible Links, Pump and Control Valve Solenoids |
| Ex400-3C Electrical Circuti (Connector) | 914 | Connector Terminal Positions, Harness Circuit, Monitor Controller, Valve Controller, Alternator |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Torque for bolt (9) | 49 N·m (5 kgf·m, 36 lbf·ft) | p. 41 |
| Torque for bolt (7) | 49 N·m (5 kgf·m, 36 lbf·ft) | p. 41 |
| Bolt (2) torque | 9.8 N·m (7.2 lbf·ft) | p. 115 |
| Hose (3 to 8) torque | 39 N·m (29 lbf·ft) | p. 115 |
| Bolt (41) torque | 137 N·m (14 kgf·m, 101 lbf·ft) | p. 201 |
| Plug (42) torque | 69 N·m (7 kgf·m, 51 lbf·ft) | p. 201 |
| Tightening Torque Hose (1) to (4) | 205 N·m | p. 231 |
| Tightening Torque Hose (5) | 69 N·m | p. 231 |
| Fuel Filter Drain Plug Torque | 4.2 ± 0.8 kg·m (30.3 ± 5.8 lb.ft / 41.2 ± 7.9 N·m) | p. 364 |
| Fuel Filter Center Bolt Torque | 2.5 ± 0.5 kg·m (18.1 ± 3.6 lb.ft / 24.5 ± 4.9 N·m) | p. 364 |
| Full flow filter filtration | 10 μm | p. 561 |
| Full flow filter bypass cracking pressure | 147 kPa | p. 561 |
