Part of the Hyundai Repair Manuals.
All 531 pages of this Hyundai R450LC-3, R450-3 service manual PDF cover one machine family: the Robex 450 hydraulic excavator, from pump device to swing and travel drives. Inside: full electrical circuit diagrams with component locations, hydraulic schematics tracing the main and pilot circuits, and a troubleshooting section that walks hydraulic and mechanical faults back to the root cause. You also get exploded views of the main control valve and work equipment, plus mechatronics coverage of the mode selection and automatic deceleration systems. Set the main relief valve at 325 kg/cm2 (4620 psi) and confirm each pump section flows its rated 360 l/min before you condemn the MCV. Your excavator is dead in the yard while you hunt for numbers. This PDF is bookmarked, keyword-searchable, and opens on any device; download it and go fix the machine.
What's Inside This Hyundai R450LC-3, R450-3 Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 1-39 | Safety Hints, Specifications |
| Structure and Function | 40-114 | Pump Device, Main Control Valve, Swing Device, Travel Device |
| Hydraulic System | 115-145 | Hydraulic Circuit, Main Circuit, Pilot Circuit |
| Electrical System | 146-201 | Component Location, Electrical Circuit, Monitoring System |
| Mechatronics System | 202-230 | Outline, Mode Selection System, Automatic Deceleration System |
| Troubleshooting | 231-305 | Hydraulic and Mechanical System |
| Maintenance Standard | 306-337 | Operational Performance Test, Major Component, Track and Work Equipment |
| Disassembly and Assembly | 338-531 | Precautions, Pump Device, Main Control Valve, Swing Device, Travel Device, Work Equipment |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| All Models | ||
| Main relief valve pressure | 325kg/cm2 (4620psi) / 350kg/cm2 (4980psi) | p. 36 |
| Overload relief valve pressure | 380kg/cm2 (5400psi) | p. 36 |
| Main pump maximum pressure | 350kg/cm2 (4980psi) | p. 35 |
| Main pump rated oil flow | 2 x 360 l/min (95.1U.S. gpm/79.2U.K. gpm) | p. 35 |
| Relief valve setting pressure | 33kg/cm2 | p. 119 |
| Abnormality code 19 | Below 18V of input voltage | p. 223 |
| Error code 01 resistance between CN-50(4)-(11) or (5)-(12) | 4 ~ 9 Ω | p. 270 |
| Over load relief pressure (Boom up, Arm, Bucket) | 380 kgf/cm2 | p. 325 |
| Engine Oil Quantity | 38 L | p. 35 |
| R450-3 | ||
| Operating Weight | 43400 kg | p. 18 |
| Swing Speed | 10.0 rpm | p. 36 |
| R450LC-3 | ||
| Operating Weight | 44300 kg | p. 19 |
Hyundai R450LC-3, R450-3 Common Problems This Manual Covers
Hyundai R450-3 hydraulics weak on all functions, boom and bucket barely lift under load
Test main relief pressure at the pump outlet. Standard setting is 325 kg/cm2 (4620 psi), rising to 350 kg/cm2 (4980 psi) under power boost, explained on page 124. If pressure tests low, adjust or replace the main relief valve and torque it to 93-108 N·m per page 406, then retest.
Manual Section: Hydraulic System Troubleshooting p. 124Boom or arm cylinder drifts down slowly with all controls in neutral, load creeps
Check the overload relief valves first; boom up, arm, and bucket circuits should hold 380 kgf/cm2 per the maintenance standard on page 325. Swap a suspect valve with a known good circuit to confirm. Replace the failed cartridge and torque it to 78-88 N·m following page 407. Still drifting, pull the cylinder and replace the piston seals.
Manual Section: Attachment System Troubleshooting p. 325Engine runs fine but no hydraulic functions respond in any lever position
Verify the safety lever is up and the pilot cutoff solenoid clicks with the key on. Test pilot pressure at the pilot line; the pilot relief valve is set at 33 kg/cm2, shown in the pilot circuit on page 119. No pressure means a plugged pilot filter or failed pilot pump; replace the filter and retest before condemning the pump.
Manual Section: Hydraulic System p. 119Machine pulls to one side during straight travel, one track slow or powerless
Check track tension on both sides, then swap the travel lines at the motors to isolate pump from motor. Measure travel speed on level ground; spec is 3.2 km/hr low and 5.1 km/hr high per page 18. If one motor stays slow, inspect its counterbalance valve and relief cartridge for sticking or contamination.
Manual Section: Travel System Troubleshooting p. 18Hydraulic oil overheats and all functions turn sluggish after an hour of digging
Drain a sample and check for cloudy, contaminated oil using the procedures. Blow out the oil cooler fins from the back side, replace the return filter, and confirm the drain filter bypass check valve opens at 1.05 kg/cm2 per page 118. Tighten every suction line clamp; air intrusion causes cavitation and rapid heat buildup.
Manual Section: Hydraulic System Troubleshooting p. 118Frequently Asked Questions
How do I reset the error code on a Hyundai R450-3?
To reset an error code on the Hyundai R450-3, you must turn the starting switch to the OFF position. This action resets the abnormality display, allowing you to check the system again by turning the starting switch back to the ON position. p. 222
What are the torque specifications for the track roller mounting bolts on a Hyundai R450-3?
The tightening torque for the track roller mounting bolts (size M22 x 1.5) on the Hyundai R450-3 is 83.2 ± 12.5 kgf·m (602 ± 90 lbf·ft). p. 341
What is the standard engine oil capacity for the Cummins M11-C engine in the R450-3?
The standard engine oil capacity for the Cummins M11-C engine is 38 liters (10 U.S. gallons). p. 35
What is the procedure for bleeding air from the hydraulic cylinders after repair?
After reassembling, start the engine at low idling. Actuate the hydraulic cylinder 4-5 times, stopping 100mm before the end of the stroke. Then, operate the piston rod to the end of its stroke to relieve the circuit, which actuates the air bleed valve. p. 339
What is the standard tightening torque for the main pump mounting socket bolts?
The standard tightening torque for the main pump mounting socket bolts (size M20 x 2.5) is 44 ± 6.6 kgf·m (318 ± 48 lbf·ft). p. 341
How quickly can I access this Hyundai R450-3 manual after buying?
This is a 531-page searchable PDF ready for immediate download. Works on any device, so pull it up on your phone while you're under the hood. No shipping, no waiting.
Can I print a copy of this Hyundai R450-3 Service Manual for the shop?
Yes. The PDF has no DRM restrictions, so print any page or section you need for your shop. Works with any standard printer.
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