Part of the Hitachi Repair Manuals.
Wrenching on a Hitachi EX27u or 35u? This 539-page Hitachi EX27u, 35u Technical and Workshop Manual PDF covers both mini excavators, from pump device to final drive. Inside: hydraulic circuit diagrams for each model, a full electrical circuit diagram, troubleshooting flowcharts for engine and actuator faults, and page after page of tightening torque charts. You also get operational performance standards, so you can test cycle times, main relief pressure, and swing motor drainage against real factory numbers instead of gut feel. Measure your bucket cylinder pin against the 35 mm standard before ordering parts; on the EX27u, ground pressure runs 29.1 kPa. No more chasing hydraulic gremlins with forum guesses and crossed fingers. Bookmarked with a full text layer, so you can jump straight to a section or search any spec from any device in the shop.
Complete the set for your EX27U, EX35U
- Parts Catalog: Hitachi EX27U Excavator Parts Catalog
- Parts Catalog: Hitachi EX35U Hydraulic Excavator Parts Catalog
Other edition of this manual
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Technical Manual - General and Specifications | 2-15 | Specifications, Engine Specification, Main Component, Electrical System, Relays, Monitor and Switches |
| Technical Manual - Hydraulic and Electrical Systems | 16-27 | Main Circuit, Pilot Circuit |
| Technical Manual - Component Operation | 28-93 | Pump Device, Swing Device, Control Valve, Pilot Valve, Travel Device, Solenoid Valve |
| Technical Manual - Operational Performance Test | 94-139 | Engine Speed, Hydraulic Cylinder Cycle Time, Main Relief Valve Set Pressure, Swing Motor Drainage, Travel Motor Drainage, Operational Performance Standard |
| Technical Manual - Troubleshooting | 140-185 | Diagnosing Procedure, Engine System Troubleshooting, Actuator Operating System Troubleshooting, Malfunction of Coolant Temperature Gauge, Electrical System Inspection |
| Hydraulic and Electrical Circuit Diagrams | 186-189 | EX27u Hydraulic Circuit Diagram, EX35u Hydraulic Circuit Diagram, EX27u, 35u Electrical Circuit Diagram |
| Workshop Manual - General Information | 190-206 | Precautions for Disassembling and Assembling, Tightening Torque Specifications, Torque Chart, Main Data and Specifications, Gasket Location, Maintenance |
| Workshop Manual - Upperstructure | 207-309 | Canopy, Counterweight, Pump Device, Control Valve, Swing Device, Pilot Valve |
| Workshop Manual - Undercarriage | 310-365 | Swing Bearing, Travel Device, Center Joint, Track Adjuster, Front Idler, Track |
| Workshop Manual - Front Attachment | 366-417 | Front Attachment, Boom Cylinder, Arm Cylinder, Bucket Cylinder, Blade Cylinder, Swing Cylinder |
| Engine - Full Repair Section (Bundled Engine Manual) | 418-539 | Main Data and Specifications, Oil Pump, Water Pump, Thermostat, Governor, Nozzle Holder Assembly |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| EX27u | ||
| Ground Pressure | 29.1 (0.30, 4.3) kPa (kgf/cm², psi) | p. 4 |
| Pin (Bucket Cylinder) Standard | 35 mm | p. 373 |
| Engine Rated Power (27u) | 16.9 kW/2450 min⁻¹ (23 PS/2450 rpm) | p. 7 |
| Main Relief Valve Set Pressure (27u) | 21.1 ± 1.0 MPa (215 ± 10 kgf/cm²) | p. 138 |
| All Models | ||
| Damaged wire connectors/cables | Broken harness between engine stop solenoid and ground. | p. 150 |
| Hydraulic system pressure is low or zero (servo system) | Failure in main pump. | p. 151 |
| Main pump failure causing loss of hydraulic power | Faulty main pump P1 or P2. | p. 153 |
| Piston Displacement | 1.496 L (91 in³) | p. 7 |
| Engine Dry Weight | 152 kg (335 Ib) | p. 7 |
| Valve Clearance (IN, EX) | 0.2 mm | p. 136 |
| EX35u | ||
| Engine Rated Power (35u) | 21.3 kW/2450 min⁻¹ (29 PS/2450 rpm) | p. 7 |
| Main Relief Valve Set Pressure (35u) | 25.0 ± 1.0 MPa (255 ± 10 kgf/cm²) | p. 138 |
