Part of the Hitachi Repair Manuals.
This 467-page Hitachi EX40u, EX50u, 50u Technical Manual puts the complete factory reference for these excavators in your hands, from main pump teardown to final engine reassembly. You get full wiring diagrams covering the main harness, engine harness, and air conditioner circuits, plus hydraulic schematics for the main and pilot circuits, a dedicated troubleshooting section for actuator and swing system faults, and page after page of torque specs and clearance charts. Torque the delivery valve holder to 39 to 44 N-m, and keep swing motor drainage under 0.5 L/min at constant max speed; anything higher and you're chasing a worn valve. No more flipping between three dog-eared photocopies trying to find the right circuit. Bookmarked by group and searchable by keyword, this PDF opens on your phone or tablet right at the machine, so you can confirm the spec before you pull a single fitting.
Complete the set for your EX40U, EX50U
- Parts Catalog: Hitachi EX50U Parts Catalog
Other edition of this manual
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 2-17 | Specifications, Working Ranges, Engine Specification, Main Component, Electrical System, Monitor and Switches |
| System | 18-27 | Hydraulic System Outline, Main Circuit, Pilot Circuit |
| Component Operation | 28-73 | Main Pump, Swing Motor, Control Valve, Pilot Valve, Travel Motor, Center Joint |
| Operational Performance Test | 74-117 | Engine Speed, Engine Compression Pressure, Travel Speed, Swing Speed, Hydraulic Cylinder Cycle Time, Main Relief Valve Set Pressure |
| Troubleshooting | 118-169 | Diagnosing Procedure, Engine System Troubleshooting, Actuator Operating System Troubleshooting, Front Attachment System Troubleshooting, Swing System Troubleshooting |
| All Diagrams | 170-180 | Hydraulic Circuit, Main Harness, Air Conditioner Harness, Electrical Circuit, Engine Harness, Frame Harness |
| General Information | 181-195 | Precautions for Disassembling and Assembling, Tightening Torque Specification, Torque Chart, Piping Joint |
| Upperstructure | 196-269 | Canopy, Counterweight, Pump Device, Control Valve, Swing Device, Pilot Valve |
| Undercarriage | 270-313 | Swing Bearing, Travel Device, Center Joint, Track Adjuster, Front Idler, Track |
| Front Attachment | 314-345 | Cylinders, Boom and Arm Cylinders, Bucket, Swing and Blade Cylinders, Maintenance Standards |
| Engine | 346-467 | General Information, Engine Disassembly, Inspection and Repair, Reassembly, Lubrication System, Cooling System, Fuel System, Troubleshooting |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Tightening Torque: delivery valve holder | 39 to 44 N·m (4 to 4.5 kgf·m, 29 to 33 lbf·ft) | p. 83 |
| Pilot Filter Hose | UNF9/16 | p. 100 |
| TRAVEL MOTOR LEAKAGE | 60 or less | p. 112 |
| SWING MOTOR DRAINAGE at constant maximum speed | (0.5 or less) | p. 113 |
| SWING MOTOR DRAINAGE with the motor relieved | (7 or less) | p. 113 |
| Engine oil pressure indicator comes on when pressure is below | 0.5±0.1 kgf/cm² | p. 152 |
| Overheat indicator comes on when coolant temperature is above | 110±3 °C (230±37 °F) | p. 153 |
| Engine cushion rubber mounting nut torque | 137 N·m (14 kgf·m, 101 lbf·ft) | p. 189 |
