Part of the Hyundai Repair Manuals.
Every one of the 533 pages in this Hyundai R320LC-7 Service Manual PDF exists for one reason: getting your R320LC-7 hydraulic excavator digging again. You get full hydraulic schematics tracing the main and pilot circuits through single and combined operation, plus wiring diagrams with connector pinouts and component locations for the entire electrical system. Open to the troubleshooting section and chase hydraulic, electrical, and mechatronics faults step by step, then follow complete disassembly and assembly procedures for the pump, main control valve, swing and travel devices. Set the main relief valve to 330 kgf/cm2 (4690 psi) and the pilot relief to 35 kgf/cm2, straight from the factory tables. A weak boom is a spec problem, not a mystery. Bookmarked with a real text layer: search a spec, jump to the section, fix the machine.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 11-35 | Safety Hints, Specifications |
| Structure and Function | 36-130 | Pump Device, Main Control Valve, Swing Device, Travel Device, Rcv Lever, Rcv Pedal |
| Hydraulic System | 131-162 | Hydraulic Circuit, Main Circuit, Pilot Circuit, Single Operation, Combined Operation |
| Electrical System | 163-207 | Component Location, Electrical Circuit, Electrical Component Specification, Connectors |
| Mechatronics System | 208-245 | Outline, Mode Selection System, Automatic Deceleration System, Power Boost System, Travel Speed Control System, Automatic Warming Up Function, Engine Overheat Prevention Function |
| Maintenance Standard | 303-339 | Operational Performance Test, Major Components, Track and Work Equipment |
| Disassembly and Assembly | 340-517 | Precaution, Tightening Torque, Pump Device, Main Control Valve, Swing Device, Travel Device, Rcv Lever, Turning Joint |
| Component Mounting Torque | 518-533 | Introduction Guide, Engine System, Electric System, Undercarriage, Structure, Work Equipment |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Main relief valve pressure | 330kgf/cm2 (4690psi) | p. 32 |
| Overload relief valve pressure | 390kgf/cm2 (5550psi) | p. 32 |
| Boom cylinder Bore dia x Rod dia x Stroke | Ø150 x Ø105 x 1480mm | p. 33 |
| Arm cylinder Bore dia x Rod dia x Stroke | Ø160 x Ø110 x 1685mm | p. 33 |
| Pilot relief valve setting pressure | 35kgf/cm2 | p. 136 |
| Track shoe mounting bolt, nut | 115 ± 5.0 kgf·m | p. 527 |
| Carrier roller mounting bolt, nut | 29.7 ± 4.5 kgf·m | p. 527 |
| Track roller mounting bolt | 57.9 ± 8.6 kgf·m | p. 528 |
| Main relief valve tightening torque | 7~8 kgf·m (50.6~57.8 lbf·ft) | p. 381 |
| Port relief valve tightening torque | 7~8 kgf·m (50.6~57.8 lbf·ft) | p. 381 |
| Socket head bolt, boom cylinder (M18) | 46.0 ± 5.0 kgf·m (333 ± 36.2 lbf·ft) | p. 494 |
| Operating Weight | 32200 kg | p. 21 |
