Part of the Doosan Repair Manuals.
Wrench on a Doosan DX420LC? This 862-page Doosan DX420LC Shop Manual PDF (OEM #K1009096AE) covers the whole track excavator family: DX300LC, 340LC, 350LC, 420LC, and 480LC. Inside: the full electrical schematic, hydraulic schematics for the A8VO200 main pump circuit, a dedicated troubleshooting, testing, and pressure-adjustment section, plus page after page of standard torque tables. You get teardown and reassembly steps for the swing motor, travel motor with planetary gearbox, main control valve, cylinders, and the 360-degree center joint. Torque the fuel tank mounting nut to 27 kg-m (200 ft lb), and set lower roller shaft-to-bushing clearance between 0.300 and 0.405 mm. Your excavator is down and the clock is running. Bookmarked with a real text layer; jump straight to any valve section or hunt a spec by keyword, right from your phone in the pit.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| Dx420Lc | 1-4 | |
| Safety | 7-50 | Track Excavator Safety |
| Specifications | 51-78 | Specification for DX420LC |
| General Maintenance | 79-116 | General Maintenance Procedures, Standard Torques |
| Upper Structure | 117-224 | Cabin, Counterweight, Fuel Tank, Fuel Transfer Pump (Opt), Swing Bearing, Swing Reduction Gear |
| Lower Structure and Chassis | 225-266 | Track Assembly |
| Engine and Drive Train | 267-276 | Drive Coupling (Main Pump) |
| Hydraulic System Troubleshooting, Testing and Adjustment | 277-312 | Hydraulic Schematic, Operation of Working Components, Pilot Pressure, Power Mode Valve, Pressure Up Valve |
| Accumulator | 313-320 | Gas-Charged Storage, Diaphragm, Precharge Pressure, P1 Rated Pressure |
| Center Joint (Swivel) | 321-334 | Hydraulic Oil Flow, 360-Degree Rotation, Disassembly, Reassembly |
| Cylinders | 335-364 | Boom Cylinder, Arm Cylinder, Piston Nut, Slipper Seal, Cylinder Performance Tests |
| Swing Motor | 365-400 | Rotary Power, Relief Valve, Parking Brake, Makeup Check Valve, Time Delay Valve |
| Travel Motor (with Gearbox) | 401-456 | Planetary Gearbox, Brake Valve, Capacity Control, Overload Valve, Disassembly and Assembly |
| Main Pump | 457-514 | A8VO200LA1KH1/63, Control Module, Rotary Groups, Drive Shaft Sealing, Gear Pump Sealing |
| Hydraulic Components and Valves (Gear Pump to Breaker EPPR Valve) | 515-696 | Gear Pump, Main Control Valve, Remote Control Valve, Travel Control Valve, Fan Motor, Solenoid Valve Assembly, Breaker EPPR Valve |
| Electrical System | 704-832 | Electrical Schematic DX420LC |
| Attachments | 833-862 | Boom and Arm, Bucket |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Bolt torque for fuel filter head plug | 27 kg•m (200 ft lb) | p. 152 |
| Maximum Output Torque (DX420LC) | 2,360 kg•m (17,070 ft lb) | p. 182 |
| Maximum Output Torque (DX340LC / DX350LC) | 2,100 kg•m (15,189 ft lb) | p. 182 |
| Lower Roller - Clearance between shaft and bushing | 0.300 - 0.405 mm | p. 238 |
| Lower Roller - Interference between roller and bushing | 0.067 - 0.132 mm | p. 238 |
| Hydraulic reservoir return line and pilot circuit filter rating | 10 micron | p. 286 |
| Reservoir intake strainer micron rating | 177 micron | p. 286 |
| Adjustment screw (2) Pi-Q control valve compensating control pressure change | -0.7 kg/cm2 per 1/2 turn | p. 301 |
| Adjustment screw (3) Pd-Q curve shift/input horsepower change | +33 kg/cm2 per 1/2 turn | p. 301 |
| Nominal sectional area of wire core less insulator | 0.85 mm2 | p. 106 |
| Filter cleaning interval | 500 hours | p. 787 |
| Fuel Tank Capacity | 550 liters | p. 66 |
