Part of the Hyundai Repair Manuals.
All 493 pages of this Hyundai Robex 250-3, 250LC-3, 250NLC-3 service manual PDF cover one machine family: the Robex crawler excavators, from pump device to travel motor. You get complete hydraulic schematics with main and pilot circuit routing, electrical wiring diagrams with component locations, and a full troubleshooting section for hydraulic and mechanical faults. Inside: step-by-step disassembly and assembly procedures for the pump, main control valve, swing device, reduction gear, and work equipment, plus maintenance standards with operational performance tests. Set the main relief valve to 320 kgf/cm2 (4550 psi) and the swing motor relief to 275 kgf/cm2 (3911 psi); the starter is a 24V Delco Remy 37MT. Your excavator is down and every idle hour costs money. Get the factory numbers, not forum guesses. Bookmarked with a full text layer; pull it up on your tablet at the machine and start wrenching.
What's Inside This Hyundai ROBEX 250-3, ROBEX 250LC-3, ROBEX 250NLC-3 Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 1-42 | Safety, Specifications, Working Range |
| Structure and Function | 43-120 | Pump Device, Main Control Valve, Swing Device |
| Hydraulic System | 121-152 | Main Circuit, Pilot Circuit, Combined Operation |
| Electrical System | 153-197 | Component Location, Electrical Circuit, Electrical Component Specification |
| Mechatronics System | 198-235 | Outline, Mode Selection System, Automatic Deceleration System |
| Troubleshooting | 236-289 | Hydraulic and Mechanical System |
| Maintenance Standard | 290-324 | Operational Performance Test, Major Component, Track and Work Equipment |
| Disassembly and Assembly | 325-493 | Precautions, Pump Device, Main Control Valve, Swing Device, Reduction Gear, Travel Device, Work Equipment |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Main relief valve pressure | 320kgf/cm2 (4550psi) [350kgf/cm2 (4980psi)] | p. 39 |
| Overload relief valve pressure | 380kgf/cm2 (5405psi) | p. 39 |
| Starting motor | Delco Remy 37MT(24V) | p. 38 |
| Starter motor | DELCO REMY 28MT 24V | p. 179 |
| Clearance between piston & cylinder bore | 0.039mm | p. 4 |
| Play between piston & shoe caulking section | 0-0.1mm | p. 310 |
| Spacer bolt torque | 9.8 ~ 11.8 kgf·m | p. 364 |
| Orifice torque | 15.0 ~ 18.0 kgf·m | p. 364 |
| Engine oil quantity | 29 L | p. 38 |
| ROBEX 250-3 | ||
| Operating weight | 23600 kg | p. 18 |
| ROBEX 250LC-3 | ||
| Operating weight | 24300 kg | p. 19 |
| ROBEX 250NLC-3 | ||
| Operating weight | 24200 kg | p. 20 |
Hyundai ROBEX 250-3, ROBEX 250LC-3, ROBEX 250NLC-3 Common Problems This Manual Covers
Hyundai Robex 250-3 hydraulic functions slow and weak, boom struggles to lift a loaded bucket
Check hydraulic oil level and inspect suction lines for air leaks first. Test main relief pressure against the 320 kgf/cm2 (4550 psi) specification with a gauge at the pump. If the relief valve needs resetting, torque it to 69.0 to 78.0 kgf·m per the chart on page 364, then work through the procedures starting on page 236.
Manual Section: Troubleshooting p. 236Loud grinding or knocking noise from the hydraulic pump area, noise gets worse under load
Drain a hydraulic oil sample and check for cloudiness or metal particles; cavitation from air ingress sounds like gravel in the pump. Tighten suction line clamps and fittings. During pump teardown, measure play between the piston and shoe caulking section; replace parts if it exceeds the 0-0.1 mm limit on page 310.
Manual Section: Hydraulic System Troubleshooting p. 310Engine cranks slowly or will not turn over at all, worst on cold mornings
Test both batteries under load before condemning the starter; a weak cell in a 24 volt series pair kills cranking speed. Clean and tighten ground straps and battery terminals, since corrosion here mimics starter failure. Confirm the starter spec (Delco Remy 28MT, 24V) on page 179, then trace the start circuit on the wiring diagram, page 155.
Manual Section: Electrical System Troubleshooting p. 179Joystick controls respond slowly or erratically, boom and arm hesitate before they move
Measure pilot pressure at the remote control valve; the pilot circuit relief valve is set at 40 kg/cm2, spec on page 125. Replace the pilot filter if pressure reads low, because contamination there starves every joystick signal. Trace the affected line through the pilot circuit diagrams in the Hydraulic System section starting on page 121.
Manual Section: Hydraulic System p. 125Hydraulic oil temperature climbs fast, temperature warning lamp comes on during normal digging
Check oil level and cooler fins first; a plugged cooler forces oil through the bypass relief valve, which opens at 3.0 kg/cm2 (43 psi), spec on page 123. Blow the cooler core clean with compressed air and inspect the oil for contamination, then follow the abnormal temperature rise procedure starting on page 236.
Manual Section: Hydraulic System Troubleshooting p. 123Upper structure swings slowly and drifts out of position when parked on a slope
Time a full swing at high idle and compare against the 12.6 rpm specification on page 39. If speed is down, test swing motor relief pressure against the 275 kgf/cm2 (3911 psi) setting. Check the swing brake for slip on a slope, then follow the swing troubleshooting steps beginning on page 236.
Manual Section: Swing System Troubleshooting p. 39Frequently Asked Questions
What are the torque specifications for the Cummins B5.9-C engine on a Hyundai ROBEX 250LC-3?
The engine mounting bolt and nut (M22 x 2.5) require a torque of 48 ± 2.0 kgf·m (347 ± 14.4 lbf·ft). The radiator mounting bolt (M12 x 1.75) requires 12.8 ± 3.0 kgf·m (92.6 ± 21.7 lbf·ft). p. 328
What is the procedure for bleeding air from the hydraulic pump after installation?
To bleed air from the hydraulic pump, remove the two air vent plugs, tighten them lightly, start the engine at low idling, and check that oil comes out from the plugs. Once oil flows, tighten the plugs fully. p. 332
How do I delete all recorded error codes on the Hyundai ROBEX 250LC-3?
To delete all recorded error codes, select the recorded error (TIME Err) display on the cluster. Then, press the engine speed up and down switches at the same time for 2 seconds or more. The cluster display will change to 'TIME Err : 00', indicating the codes have been deleted. p. 216
What is the standard clearance for the track roller shaft and bushing?
The standard clearance between the track roller shaft and bushing is 0.35 to 0.455 mm, with a clearance limit of 1.5 mm. p. 319
What is the tightening torque for the travel motor mounting bolts?
The travel motor mounting bolts (M16 x 2.0) should be tightened to a torque of 25.7 ± 4.0 kgf·m (186 ± 29 lbf·ft). p. 328
Is this Hyundai Robex 250-3 manual a download or a disc?
You get a 493-page searchable PDF that downloads instantly after checkout. Open it on your laptop, tablet, or phone, and bring it right to the shop floor.
Is printing allowed for this Hyundai Robex 250-3 Service Manual?
Absolutely. No DRM or copy protection. Print the whole manual or just the pages you need. Any home or office printer works.
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