Part of the Doosan Repair Manuals.
Need factory-level data for your Doosan DX255LC-3 excavator? This 874-page Doosan DX255LC-3 shop manual PDF (OEM #950106-00374E) covers everything from the swing bearing to the track assembly, and its procedures carry over to the DX140LC-3, 180LC-3, 225LC-3, and 300LC-3. Inside: complete hydraulic schematics, electrical wiring diagrams, and a dedicated troubleshooting, testing, and adjustment section spanning pilot pressure, the power mode valve, and pump input power control. You also get step-by-step teardown and reassembly for the main pump, swing device, travel device, cylinders, and center joint, backed by standard torque tables. Set track tension to 320-340 mm on normal ground, stretch it to 340-370 mm in mud or snow, and keep a 27 mm socket handy for the grease valve. Your machine is down; get factory numbers, not forum guesses. Bookmarked with a live text layer: jump to any section or type the spec you need.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Safety | 5-72 | Track Excavator Maintenance Safety |
| Specifications | 73-102 | Specifications for DX255LC-3 |
| General Maintenance | 103-140 | Standard Torques |
| Upper Structure | 141-202 | Cabin, Counterweight, Fuel Tank, Fuel Transfer Pump, Swing Bearing |
| Lower Structure and Chassis | 203-236 | Track Assembly |
| Engine and Drivetrain | 237-266 | Engine Coolant Heater, Drive Coupling |
| Hydraulic System Troubleshooting, Testing and Adjustment | 267-302 | Troubleshooting, Pilot Pressure, Power Mode Valve, Pressure Up Valve, Pump Input Power Control |
| Accumulator | 303-310 | Gas-Charged Storage, Precharge Pressure, Diaphragm, Specifications |
| Center Joint (Swivel) | 311-324 | Inspection, Testing, Disassembly, Reassembly, Slipper Seal |
| Cylinders | 325-362 | Theory of Operation, Disassembly, Reassembly, Piston Jig, Dust Wiper Jig, Slipper Seal Straightening Jig |
| Swing Device | 363-414 | Swing Bearing, Reduction Gear, Reactionless Valve, Brake Part, Maintenance Standards |
| Travel Device | 415-472 | Operation Manual, Disassembly, Reassembly, Performance Check Test, Seal Information |
| Main Pump | 473-518 | Axial Piston Pump, Regulator, Disassembly, Reassembly, Flow Control |
| Gear Pump, Main Control Valve, Breaker EPPR Valve, Hydraulic Schematic | 519-682 | |
| Electrical System | 683-848 | Electrical Supply System, Engine Starting Circuit, Engine Preheating System, Charging System, Monitoring System, Graphic Information Area Display, User Menu, Special Menu |
| Attachments | 849-874 | Boom and Arm, Bucket |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Thermal limiter open temperature | 150 ±5°C (302 ±41°F) | p. 190 |
| Thermal limiter reactivation temperature | 143°C (289°F) | p. 190 |
| Recommended track tension distance for Normal terrain | 320 - 340 mm (12.60 - 13.39 in) | p. 212 |
| Recommended track tension distance for Muddy, Sandy or Snowy terrain | 340 - 370 mm (13.39 - 14.57 in) | p. 212 |
| Tightening Torque for M6 Hex Bolt | 120 ±20 kg•cm | p. 388 |
| Tightening Torque for M10 Hex Socket Head Bolt | 300 ±50 kg•cm | p. 388 |
| Fuel filter replacement period | 500 hr | p. 719 |
| Pilot filter replacement period | 1,000 hr | p. 719 |
| Return filter replacement period | 1,000 hr | p. 719 |
| Engine oil filter replacement period | 500 hr | p. 719 |
| Main Relief Pressure (Normal) | 330 kg/cm2 | p. 96 |
| Main Relief Pressure (Pressure Up) | 350 kg/cm2 | p. 96 |
