Doosan DX420LC User manual

K1009096E Shop Manual
Copyright 2005 Doosan
Doosan reserves the right to improve our products in a continuing process to provide the best possible
product to the market place. These improvements can be implemented at any time with no obligation to
change materials on previously sold products.It is recommended that consumers periodically contact their
distributors for recent documentation on purchased equipment.
This documentation may include attachments and optional equipment that is not available in your
machine's package.Please call your distributor for additional items that you may require.
Illustrations used throughout this manual are used only as a representation of the actual piece of
equipment, and may vary from the actual item.
Shop Manual
K1009096E
Serial Number 5001 and Up
DX420LC

Product Label
Instructions
Trim OutThe Label Along
The Lines And Insert Into
Pocket OnThe Binder Spine
DX420LC Serial Number 5001 and Up Pub.No. K1009096E
Pub. No. K1009096E

Table of Contents
Page I
1
Table of Contents
Safety
Track Excavator Safety......................................................................... SP000256
Specifications
Specification for DX420LC.................................................................... SP000257
General Maintenance
General Maintenance Procedures........................................................ SP000016
Standard Torques................................................................................. SP000017
Upper Structure
Cabin .................................................................................................... SP000018
Counterweight....................................................................................... SP000265
Fuel Tank.............................................................................................. SP000264
Swing Bearing....................................................................................... SP000262
Swing Reduction Gear.......................................................................... SP000249
Lower Structure and Chassis
Track Assembly .................................................................................... SP000263
Air Conditioner...................................................................................... SP000025
Engine and Drive Train
Drive Coupling (Main Pump)................................................................. SP000026
Hydraulics
Hydraulic System Troubleshooting, Testing and Adjustment ............... SP000273
Accumulator.......................................................................................... SP000028
Center Joint (Swivel)............................................................................. SP000181
Cylinders............................................................................................... SP000030

Table of Contents
Page II
Swing Motor.......................................................................................... SP000261
Travel Motor (With Gearbox) ................................................................ SP000266
Main Pump............................................................................................ SP000186
Control Valve (KVMG-400-DA)............................................................. SP000187
Remote Control Valve (Work Lever / Joystick)..................................... SP000189
Travel Control Valve (With Damper)..................................................... SP000070
Solenoid Valve Assembly ..................................................................... SP000191
Breaker EPPR Valve (Opt) ................................................................... SP000192
Fan Motor (Vane Type)......................................................................... SP000209
Gear Pump (Fan Cooling Drive) ........................................................... SP000208
Fan Cooling Flow In-Out Change Valve ............................................... SP000207
Hydraulic Schematic (DX420LC).......................................................... SP000274
Electrical System
Electrical System .................................................................................. SP000269
Electrical Schematic (DX420LC) .......................................................... SP000275
Attachments
Boom and Arm...................................................................................... SP000463
Bucket................................................................................................... SP000072

1
Safety

SP000256
Page 1
Track Excavator Safety
SP000256
TRACK EXCAVATOR SAFETYSP000256
Track
Excavator
Safety
Edition 1

Track Excavator Safety
SP000256
Page 2
MEMO

SP000256
Page 3
Track Excavator Safety
Table of Contents
Track Excavator Safety
Safety Precautions................................................ 5
Applicable Models................................................. 5
To the Operator of a
DOOSAN Daewoo Excavator
.............................................................................. 6
General Safety Essentials .................................. 10
Location of Safety Labels ................................... 11
Summary of Safety Precautions for Lifting in
Digging Mode ..................................................... 12
Unauthorized Modifications ................................ 13
General Hazard Information ............................... 13
Before Starting Engine ....................................... 22
Machine Operation ............................................. 26
Maintenance ....................................................... 33
Battery ................................................................ 42
Towing................................................................. 44
Shipping and Transportation ............................... 45
Lifting With Sling ................................................. 45

Track Excavator Safety
SP000256
Page 4
MEMO

Track Excavator Safety
Page 5
SP000256
SAFETY PRECAUTIONS
APPLICABLE MODELS
The contents of this section apply to the following models and
serial number ranges.
CAUTION!
Follow all safety recommendations and safe shop practices
outlined in the front of this manual or those contained
within this section.
Always use tools and equipment that are in good working
order.
Use lifting and hoisting equipment capable of safely
handling load.
Remember, that ultimately safety is your own personal
responsibility.
MODEL SERIAL NUMBER RANGE
DX420LC 5001 and Up

SP000256Track Excavator Safety
Page 6
TO THE OPERATOR OF A
DOOSAN DAEWOO
EXCAVATOR
Please respect the importance of taking responsibility for your
own safety, and that of other people who may be affected by
your actions.
The safety information on the following pages is organized into
the following sections:
1. “General Safety Essentials” on page 1-10
2. “Location of Safety Labels” on page 1-11
3. “Summary of Safety Precautions for Lifting in Digging
Mode” on page 1-12
4. “Unauthorized Modifications” on page 1-13
5. “General Hazard Information” on page 1-13
6. “Before Starting Engine” on page 1-22
7. “Machine Operation” on page 1-26
8. “Maintenance” on page 1-33
9. “Battery” on page 1-42
10. “Towing” on page 1-44
11. “Shipping and Transportation” on page 1-45
12. “Lifting With Sling” on page 1-45
DANGER!
Unsafe use of the excavator could lead to serious injury or
death. Operating procedures, maintenance and equipment
practices or traveling or shipping methods that do not
follow the safety guidelines on the following pages could
cause serious, potentially fatal injuries or extensive damage
to the machine or nearby property.

Track Excavator Safety
Page 7
SP000256
WARNING!
Improper operation and maintenance of this machine can
be hazardous and could result in serious injury or death.
Operator and maintenance personnel should read this
manual thoroughly before beginning operation or
maintenance.
Keep this manual in the storage compartment to the rear of
the operator's seat, and have all personnel involved in
working on the machine read the manual periodically.
Some actions involved in operation and maintenance of the
machine can cause a serious accident, if they are not done
in a manner described in this manual.
The procedures and precautions given in this manual apply
only to intended uses of the machine.
If you use your machine for any unintended uses that are
not specifically prohibited, you must be sure that it is safe
for any others. In no event should you or others engage in
prohibited uses or actions as described in this manual.
DOOSAN delivers machines that comply with all applicable
regulations and standards of the country to which it has
been shipped. If this machine has been purchased in
another country or purchased from someone in another
country, it may lack certain safety devices and
specifications that are necessary for use in your country. If
there is any question about whether your product complies
with the applicable standards and regulations of your
country, consult DOOSAN or your DOOSAN distributor
before operating the machine.

SP000256Track Excavator Safety
Page 8
Learn the Signal Words Used with the
Safety Alert Symbol
The words "CAUTION," "WARNING," and "DANGER" used
throughout this manual and on decals on the machine indicate
degree of risk of hazards or unsafe practices. All three degrees
of risk indicate that safety is involved. Observe precautions
indicated whenever you see the Safety Alert "Triangle," no
matter which signal word appears next to the "Exclamation
Point" symbol.
SAFETY ALERT SYMBOL
Be Prepared - Get to Know All Operating and Safety
Instructions.
This is the Safety Alert Symbol. Wherever it appears in this
manual or on safety signs on the machine you should be
alert to the potential for personal injury or accidents.
Always observe safety precautions and follow
recommended procedures.
CAUTION!
This word is used on safety messages and safety labels and
indicates potential of a hazardous situation that, if not
avoided, could result in minor or moderate injury. It may
also be used to alert against a generally unsafe practice.
WARNING!
This word is used on safety messages and safety labels and
indicates potential of a hazardous situation that, if not
avoided, could result in serious injury or death. It may also
be used to alert against a highly unsafe practice.
DANGER!
This word is used on safety messages and safety labels and
indicates an imminent hazard of a situation that, if not
avoided, is very likely to cause death or extremely serious
injury. It may also be used to alert against equipment that
may explode or detonate if handled or treated carelessly.

Track Excavator Safety
Page 9
SP000256
Safety precautions are described in SAFETY from page -11 on.
DOOSAN cannot predict every circumstance that might involve
a potential hazard in operation and maintenance. Therefore the
safety messages in this manual and on the machine may not
include all possible safety precautions. If any procedures or
actions not specifically recommended or allowed in this manual
are used, you must be sure that you and others can do such
procedures and actions safely and without damaging the
machine. If you are unsure about the safety of some procedures,
contact a DOOSAN distributor.

SP000256Track Excavator Safety
Page 10
GENERAL SAFETY ESSENTIALS
Accessory Applications
The excavator has been primarily designed for moving earth
with a bucket. For use as a grapple or for other object handling,
contact DOOSAN for proper installation and application. Lifting-
work applications (unless restricted or prohibited by local
regulations) are permitted in approved lift configuration, to rated
capacity only, with no side-loading. DO NOT use the machine for
activities for which it was not intended. DO NOT use the bucket
for lifting work, unless lift slings are used in the approved
configuration.
Use of an accessory hydraulic hammer (breaker), work in rough
terrain, demolition applications or other hazardous operation
may require installation of additional protective structures to
safeguard the operator.
Lifting Capacity Rating Configuration
Lifting capacity ratings that are printed at the end of this safety
section are based on the machine being level, on a firm
supporting surface, with hooks and slings attached in approved
configuration. Loads must be balanced and supported evenly.
Use tag lines to keep the load steady if wind conditions and
large surface area are a problem. Work crew hand signals,
individual tasks and safe procedures should all be universally
understood before the lift is made .
IMPORTANT
Before using the excavator to make lifts check municipal
and regional regulations or statutes that could apply.
Governing ordinances may require that all heavy lifting be
done with single purpose equipment specifically designed
for making lifts, or other local restrictions may apply.
Making heavy lifts with a general purpose excavator that
can be used for digging, loading, grading or other work may
be expressly forbidden by a regional injunction or other
legal prohibition. Always follow all of the other instructions,
guidelines and restrictions for Safe Lifting in the Operation
and Maintenance Manuals.

Track Excavator Safety
Page 11
SP000256
LOCATION OF SAFETY LABELS
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.
Figure 1
813
5
3126
15
12
FG001823
1411 9 11 10
2190-3311
16
0
7
4

SP000256Track Excavator Safety
Page 12
SUMMARY OF SAFETY
PRECAUTIONS FOR LIFTING IN
DIGGING MODE
To lift safely while in Digging Mode, the following items must be
evaluated by the operator and the work site crew.
• Condition of ground support.
• Excavator configuration and attachments.
•Weight, lifting height and lifting radius.
• Safe rigging of the load.
• Proper handling of the suspended load.
Tag lines on opposite sides of the load can be very helpful in
keeping a suspended load secure, if they are anchored safely to
control points on the ground.
Always engage the "Digging Mode" control on the Instrument
Panel before using the excavator for lifting work.
DANGER!
Unsafe use of the excavator while making rated lifts could
cause serious, potentially fatal injuries or extensive damage
to the machine or nearby property. Do not let anyone
operate the machine unless they've been properly trained
and understand the information in the Operation and
Maintenance Manual.
WARNING!
NEVER wrap a tag line around your hands or body.
NEVER rely on tag lines or make rated lifts when wind gusts
are more than 48.3 km/h (30 MPH). Be prepared for any type
of wind gust when working with loads that have a large
surface area.
WARNING!
If you need more information or have any questions or
concerns about safe operating procedures or working the
excavator correctly in a particular application or in the
specific conditions of your individual operating
environment, please consult your local
DOOSAN
representative.