The document provides maintenance information for the engine of a DX420LC-3 excavator, including:
- Safety instructions and introduction regarding repair work safety.
- Descriptions of the engine number, structure, fuel system, cooling system, lubrication system, and induction system.
- Diagrams of components like the common rail, fuel supply pump, injector, water pump, thermostat, oil pump, and VGT system.
- Information on maintenance procedures, part numbers, inspection items, and more for the engine and related systems.
Vina Score and Vin Min for almost all the models 2024
Daewoo doosan dx420 lc 3 excavator service repair manual (serial number 10001 and up)
1. Original InstructionsCopyright DOOSAN 2012
Serial Number 10001 and Up
Shop Manual
DX420LC-3 Excavator
950106-00398E
July 2012
DOOSAN and the DOOSAN logo are registered
trademarks of DOOSAN Corporation in the United
States and various other countries around the
world.
2. Table of Contents
Page I
1Table of Contents
Safety
Track Excavator Maintenance Safety................................................... SP002322
Specifications
Specification for DX420LC-3 ................................................................ SP002670
General Maintenance
General Maintenance Instructions........................................................ SP002454
Standard Torques................................................................................. SP002404
Upper Structure
Cabin .................................................................................................... SP002324
Counterweight....................................................................................... SP002697
Fuel Tank.............................................................................................. SP002699
Fuel Transfer Pump (Option)................................................................ SP002560
Swing Bearing....................................................................................... SP002329
Lower Structure and Chassis
Track Assembly .................................................................................... SP002561
Engine and Drivetrain
Engine................................................................................................... SP002654
Engine Coolant Heater (Option) ........................................................... SP002328
Drive Coupling (Main Pump)................................................................. SP002562
Hydraulics
Hydraulic System Troubleshooting, Testing and Adjustment ............... SP002655
Accumulator.......................................................................................... SP002455
Center Joint (Swivel)............................................................................. SP002545
3. Table of Contents
Page II
Cylinders............................................................................................... SP002769
Swing Device........................................................................................ SP002653
Travel Device........................................................................................ SP002609
Main Pump............................................................................................ SP002567
Gear Pump ........................................................................................... SP002568
Fan Motor for Oil Cooler ....................................................................... SP002576
Fan Motor for Radiator.......................................................................... SP002577
Fan Pump ............................................................................................. SP002553
Main Control Valve ............................................................................... SP002656
Remote Control Valve (Work Lever / Joystick)..................................... SP002578
Travel Control Valve (with Damper)...................................................... SP002381
Solenoid Valve Assembly ..................................................................... SP002406
Breaker EPPR Valve (Option) .............................................................. SP002458
Hydraulic Schematic............................................................................. SP002671
Electrical System
Electrical System .................................................................................. SP002571
Electrical Schematic ............................................................................. SP002572
Attachments
Boom and Arm...................................................................................... SP002669
Bucket................................................................................................... SP002421
5. SP002322
Page 5
Track Excavator Maintenance Safety
SAFETY INSTRUCTIONS
APPLICABLE MODELS
The contents of this section apply to the following models and
serial number ranges.
WARNING
AVOID DEATH OR SERIOUS INJURY
Instructions are necessary before operating or servicing
machine. Read and understand the Operation and
Maintenance Manual and signs (decals) on machine. Follow
warnings and instructions in the manuals when making
repairs, adjustments or servicing. Check for correct
function after adjustments repairs or service. Untrained
operators and failure to follow instructions can cause death
or serious injury.
MODEL SERIAL NUMBER RANGE
DX140LC-3 1001 and Up, 50001 and Up
DX180LC-3 1001 and Up, 50001 and Up
DX225LC-3 1001 and Up, 50001 and Up
DX255LC-3 1001 and Up, 50001 and Up
DX300LC-3 1001 and Up, 50001 and Up
DX340LC-3 1001 and Up, 10001 and Up
DX350LC-3 1001 and Up, 10001 and Up
DX380LC-3 10001 and Up
DX420LC-3 10001 and Up
6. SP002322Track Excavator Maintenance Safety
Page 6
SAFETY MESSAGES
Safety messages and safety decals included in this manual and
on the machine provide instructions how to operate, service and
maintain the machine. Safety messages and safety decals
indicate potential hazards and describe safety precautions
required to avoid hazards. Operator and maintenance personnel
should read and understand these safety messages and decals
before beginning operation or maintenance.
Signal Words
The signal words "DANGER", "WARNING", "CAUTION" are
used throughout safety messages and safety decals in this
manual or on the machine. They indicate an existence of, and
the relative seriousness of, a hazard. All three indicate that a
safety risk is involved. Observe the precautions indicated
whenever a Safety Alert Symbol is present, no matter which
signal word appears next to it.
SAFETY ALERT SYMBOL
Be Prepared - Get to Know All Operating and Safety
Instructions.
This is a Safety Alert Symbol. Wherever it appears in this
manual or on safety decals on the machine, you must be
alert to the potential for personal injury or accidents.
Always observe safety precautions and follow
recommended procedures.
DANGER
DANGER - This signal word is used on safety messages and
safety labels and indicates an imminently hazardous situation
which, if not avoided, will result in death or serious injury.
WARNING
WARNING - This signal word is used on safety messages and
safety labels and indicates a potentially hazardous situation
which, if not avoided, could result in death or serious injury.
7. SP002322
Page 7
Track Excavator Maintenance Safety
Other Signal Words
In addition to safety signal words, the following signal words are
used to indicate proper and effective use of machine.
The word "NOTE" identifies information for effective use.
SAFETY DECALS
Location of safety labels (decals) can vary from unit to unit.
Refer to appropriate Operation and Maintenance Manual, and
parts manual for your unit.
Always replace damaged or faded decals.
CAUTION
CAUTION - This signal word is used on safety messages
and safety labels and indicates a potentially hazardous
situation which, if not avoided, could result in minor or
moderate injury.
IMPORTANT
This signal word identifies procedures which must be
followed to avoid damage to machine.
9. SP002654
Page 5
Engine
SAFETY INSTRUCTIONS
APPLICABLE MODELS
The contents of this section apply to the following models and
serial number ranges.
WARNING
AVOID DEATH OR SERIOUS INJURY
Instructions are necessary before operating or servicing
machine. Read and understand the Operation and
Maintenance Manual and signs (decals) on machine. Follow
warnings and instructions in the manuals when making
repairs, adjustments or servicing. Check for correct
function after adjustments repairs or service. Untrained
operators and failure to follow instructions can cause death
or serious injury.
MODEL SERIAL NUMBER RANGE
DX420LC-3 10001 and Up
10. SP002654Engine
Page 6
INTRODUCTION
Safety Information
Repair Work Safety Information
1. Use an engine stand when removing the engine from the
equipment. Be sure not to place the engine directly on the
ground or allow the oil pan to come into contact with the
ground or a hard surface.
2. When performing a procedure with two or more people,
make sure to ensure each other's safety.
3. When repairing the electrical system, make sure to
disconnect the cable from the negative (-) battery terminal
before working. Keep arcs, sparks and cigarettes away
when removing the battery cover.
4. Do not leave the engine running for an extended period of
time or perform painting in a poorly ventilated working
environment.
5. Make sure to use only the special tools if the procedure
requires them for the work. Performing the procedure using
other tools can cause damage to parts or personal injury.
6. Inspect the tools, instruments, and special tools regularly,
and prepare them before working. Do not use damaged or
worn out tools such as a wrench that has lost its edges, a
hammer with frayed edges, or a chipped chisel.
7. When performing work using a device such as a grinder,
crane or welder, make sure to pay sufficient attention to the
handling precautions. Wear work clothes and safety
equipment in the other operations as required.
8. Be sure to check that there are no fuel leaks when
performing maintenance on the fuel systems.
9. When handling flammable materials, be careful to not let
them catch fire. Also make sure to wipe away any oil that
sticks to rubber parts, as it can cause deterioration.
Replacement Parts and Part Number Safety Information
1. Whenever disassembly is performed, make sure to replace
the packing, oil seals, O-rings, crimping locknuts, bending
lock plate, and split pins, etc., with new ones.
2. Since the part numbers indicated in this manual may differ
from the supply system and are subject to change, make
sure to check the supply system and part numbers in the
parts catalog.
FG023344
Figure 1
Sun Gear Holder
Coupling
FG022706
Figure 2
FG023345
Figure 3
11. SP002654
Page 7
Engine
SERVICE INFORMATION GUIDE
Contents Included in Service Information
1. Removal
Includes the removal procedure for repairing parts and
devices, etc.
2. Installation
Includes the installation procedure for repairing parts and
devices, etc.
3. Disassembly
Includes the disassembly procedure for performing an
overhaul of a unit or assembly part, etc.
4. Assembly
Includes the assembly procedure for performing an
overhaul of a unit or assembly part, etc.
5. Inspection
Includes the inspection items for the parts that particularly
require inspection to ensure continued performance of
parts and devices. The standard values, set values, and
limits for use of parts are included if they have these
specifications set.
6. Cleaning
Includes the cleaning procedure for parts and devices, etc.
7. Preparation
Includes the preparatory procedure necessary before
removing parts and devices, etc.
8. Adjustment
Includes the adjustment procedure when parts have to be
adjusted to set values or standard values when performing
assembly or installation.
9. Measurement
Includes the measurement procedure to judge if parts are
installed correctly, etc.
10. Drain
Includes the draining procedure of oil, etc.
11. Refill
Includes the refilling procedure of oil, etc.
12. SP002654Engine
Page 8
12. Air Removal
Includes the air removal procedure when air removal is
necessary after replacing oil, etc. Writing Includes the
writing procedure necessary after replacing the ECM or
supply pump.
13. Precaution
Includes the maintenance precautions specific to each item.
14. Disconnection
Includes the disconnection procedures of wiring, piping, etc.
15. Connection
Includes the connection procedures for wiring, piping, etc.
16. Setting
Includes the setting procedure necessary after replacing
the ECM, etc.
17. Replacement
Includes the replacement procedure for parts and oils, etc.
18. Prioritized DTC
Includes DTCs that need to be diagnosed and resolved
before the relevant DTC when multiple DTCs are detected.
19. Diagnosis
Includes the diagnosis procedure for troubleshooting
symptoms. DTCs are listed in the descending order of priority.
20. Confirmation of Problem Resolution
Includes procedures to clear the DTC and any necessary
confirmation steps using numeric values, etc.
21. Functional Description
Includes detailed functional description related to
functional inspection.
22. Symptom Description
Includes detailed symptom descriptions related to
diagnosis by symptom.
23. DTC Description
Includes circuit description related to DTCs.
24. Setting Conditions
Includes the preconditions and judgment conditions
required for the ECU to detect a DTC.
25. Action Upon Setting
Includes information related to control actions taken by the
ECU when DTCs are set.
26. Items Related to ETM
Items related to the ETM are included in "Using the Wiring
Diagram".
13. SP002654Engine
Page 32
Function, Structure, Operation
Engine Number
Figure 15
Reference
Number
Description
1 Engine Number Stamping 2 Function, Structure, Operation
Reference
Number
Description
16. SP002654
Page 35
Engine
Fuel System
Figure 19
IMPORTANT
• Since the high-precision fuel system has been
adopted, take care to prevent any foreign material from
entering the fuel system.
• Do not disassemble the supply pump, common rail, or
injector.
Reference
Number
Description
1 Injector
2 Fuel Filter
3 Fuel Tank
4 Pre-fuel Filter
5 Supply Pump
6 Common Rail
Reference
Number
Description
18. SP002654
Page 37
Engine
Fuel Supply Pump
Figure 21
Reference
Number
Description
1 Air Bleeder
2 Pump Control Valve (PCV)
3 Overflow Valve
4 CMP Sensor
Reference
Number
Description
19. SP002654Engine
Page 38
Injector
Fuel Filter
1
3
2
FG023364
Figure 22
Reference
Number
Description
1 Injector Assembly
2 Gasket
3 O-ring
Reference
Number
Description
2
1
3
4 FG023365
Figure 23
Reference
Number
Description
1 Priming Pump
2 Air Bleed
3 Case
4 Drain Plug
20. SP002654
Page 39
Engine
Cooling System
The cooling system is a forced-circulation system, and its main
components are the water pump, thermostat and radiator. It
cools the inside of the engine, oil cooler, EGR gas, etc.
Figure 24
Reference
Number
Description
1 Sub-tank
2 Air Leak Pipe
3 EGR Cooler
4 Oil Cooler
5 Thermostat
6 Water Pump
7 Radiator
Reference
Number
Description
21. SP002654Engine
Page 40
Water Pump
The water pump is a centrifugal impeller type pump and is driven
by the engine fan belt.
Figure 25
Reference
Number
Description
1 Pulley Center
2 Bearing
3 Seal Unit
4 Impeller
5 Shaft
6 Oil Seal
7 Retaining Ring
8 Oil Seal
Reference
Number
Description
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23. SP002654
Page 41
Engine
Thermostat
The thermostat is a wax pellet type and its initial open valve
temperature is set to 80°C (176°F). The structure allows the
water temperature to be fine adjusted, and it is assembled inside
the thermostat housing unit.
Lubrication System
A gear type oil pump, full-flow bypass integrated oil filter, water-
cooling oil cooler, oil relief valve and piston cooling oil jet are
adopted for the lubrication system.
FG023368
Figure 26
Figure 27
