Part of the Hyundai Repair Manuals.
Need the factory answer for your Hyundai R320LC-9 or R320NLC-9 hydraulic excavator? This 541-page Hyundai R320LC-9, R320NLC-9 shop manual PDF covers the pump device, main control valve, swing and travel drives, and the R320LC-9 High Walker variant. You get hydraulic circuit schematics tracing main and pilot lines, full electrical wiring diagrams with connector pinouts, and a thick troubleshooting section spanning hydraulic, electrical, and mechatronics faults. Open the disassembly chapters and follow step-by-step teardowns for the swing device, travel motor, turning joint, and boom, arm, and bucket cylinders. Set the main relief valve at 350 kgf/cm2 (4980 psi) and confirm pilot relief pressure hits 40 kgf/cm2 before you button it up. No more chasing hydraulic faults with a gauge and a hunch. Bookmarked by system and keyword-searchable; jump to the spec, then get back on the sticks.
What's Inside This Hyundai R320LC-9, R320NLC-9 Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 11-41 | Safety Hints, Specifications |
| Structure and Function | 42-120 | Pump Device, Main Control Valve, Swing Device, Travel Device, Rcv Lever, Rcv Pedal |
| Hydraulic System | 121-152 | Hydraulic Circuit, Main Circuit, Pilot Circuit |
| Electrical System | 153-203 | Component Location, Electrical Circuit, Connectors |
| Mechatronics System | 204-260 | Outline, Mode Selection System, Monitoring System |
| Maintenance Standard | 328-362 | Operational Performance Test, Major Components, Track and Work Equipment |
| Disassembly and Assembly | 363-525 | Precaution, Tightening Torque, Pump Device, Main Control Valve, Swing Device, Travel Device, Rcv Lever, Turning Joint |
| Component Mounting Torque | 526-541 | Introduction Guide, Engine System, Electric System, Undercarriage, Structure, Work Equipment |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Main relief valve pressure | 350 kgf/cm2 (4980 psi) [380 kgf/cm2 (5400 psi)] | p. 38 |
| Remote control valve operating pressure (Minimum) | 6.5 kg/cm2 (92 psi) | p. 39 |
| Remote control valve operating pressure (Maximum) | 26 kg/cm2 (370 psi) | p. 39 |
| Bypass relief valve opening pressure | 1.5 kgf/cm2 | p. 124 |
| System pressure regulator relief setting (Boom, Arm, Bucket) | 350(380)±10 kgf/cm2 | p. 348 |
| System pressure regulator relief setting (Travel) | 350±10 kgf/cm2 | p. 348 |
| Main relief valve (601) tightening torque | 7.0 ~ 8.1 kgf·m | p. 411 |
| Socket head bolt (Bucket cylinder, item 23) | 32.0±3.0 kgf·m | p. 502 |
| Socket head bolt (Boom cylinder, item 23) | 46.0±5.0 kgf·m | p. 502 |
| Engine oil quantity | 35 L | p. 37 |
| R320LC-9 | ||
| Operating weight | 32200 kg | p. 22 |
| R320NLC-9 | ||
| Operating weight | 32000 kg | p. 23 |
Hyundai R320LC-9, R320NLC-9 Common Problems This Manual Covers
Hyundai R320LC-9 excavator all hydraulic functions weak, digging power low, cannot build normal working pressure
Test main pump pressure with a gauge at the pump outlet; the main relief setting is 350 kgf/cm2 (4980 psi), per page 38. If pressure is low on every circuit, remove the main relief valve, inspect the seat and spring, and clean or replace the cartridge. Torque it to 7.0 to 8.1 kgf·m on reinstall (page 411).
Manual Section: Hydraulic and Mechanical System Troubleshooting p. 38Boom or arm creeps down with pilot levers in neutral, machine parked and warm
Swap the suspect port relief valve with a matching cartridge from another circuit. If the drift follows the valve, replace it and torque to 12.2 to 14.3 kgf·m, per page 412. If the drift stays put, reseal the cylinder; torque the boom cylinder piston to 150±15.0 kgf·m during reassembly (page 502).
Manual Section: Hydraulic and Mechanical System Troubleshooting p. 412Swing motor weak and noisy, upper structure will not rotate at full speed
Check swing circuit pressure against the 300±10 kgf/cm2 relief setting from the performance test data on page 348. If pressure is good but rotation still drags, verify the swing parking brake releases at 40 kgf/cm2 (page 346). Drain an oil sample and look for contamination sticking the swing valve spool.
Manual Section: Hydraulic and Mechanical System Troubleshooting p. 348All working devices respond slowly, levers feel soft, engine running at full throttle
Measure pilot pressure first; the pilot relief valve is set at 40 kgf/cm2, per page 126. Then check secondary pressure at each RCV port, which should read 5 to 20.5 kgf/cm2 through lever travel (page 109). If pilot supply is low, replace the pilot line filter and inspect the pilot pump for wear.
Manual Section: Hydraulic System p. 126Boom will not lower when lever is pushed, all other functions work fine
Support the attachment safely, then measure pilot pressure at the boom-down signal line; the remote control valve delivers 6.5 to 26 kg/cm2 through full stroke, per page 39. If the signal is present, remove the boom hold valve, flush the spool and orifice with clean solvent, inspect for scoring, and replace the valve if the spool sticks.
Manual Section: Hydraulic and Mechanical System Troubleshooting p. 39Frequently Asked Questions
How do I clear the fault codes on the Hyundai R320LC-9 cluster?
To clear logged fault codes, open the 'Monitoring' menu on the cluster, select 'Delete logged fault', and confirm the deletion. This procedure is detailed in the 'Self-Diagnostic System' section. p. 218
What does the communication fault HCESPN 840, FMI 2 mean on the cluster?
This fault indicates a communication error between the cluster and the MCU. You should check the wiring harness and connections between CN-56 (pins 4, 8) and CN-5 (pins 1, 2), or between CN-5 (pins 1, 2) and CN-51 (pins 23, 33). p. 286
What is the tightening torque for the main relief valve (601) on the main control valve?
The tightening torque for the main relief valve (601) is 7.0 to 8.1 kgf·m (50.6 to 58.6 lbf·ft). p. 412
What is the standard clearance between the piston and cylinder block bore for the main pump?
The standard clearance between the piston and cylinder block bore for the main pump is 0.043 mm, with a recommended replacement value of 0.070 mm. p. 349
What is the hydraulic tank capacity for the R320LC-9?
The hydraulic tank capacity is 190 liters (50 U.S. gal), and the total system capacity is 330 liters (87 U.S. gal). p. 41
Is this Hyundai R320LC-9 manual a download or a disc?
Instant PDF download. You get the full 541-page searchable Shop Manual immediately after payment. Open it on your laptop, tablet, or phone right in the shop.
Are there any print restrictions on this Hyundai R320LC-9 manual?
Yes. The PDF is DRM-free, so printing works from any reader and any printer.
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