Kubota Super 2 KX 91-3, Super 2 U 35-3 Operator's Manual

MODELS

OPERATOR'S MANUAL

1BAAGABAP0290

1BAAGABAP0280

English (Australia)
Code No. RC468-8131-4

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PRINTED IN JAPAN

©

KUBOTA Corporation 2007

READ AND SAVE THIS MANUAL

KX91-3 · U35-3

KUBOTA Corporation is ···

Since its inception in 1890, KUBOTA Corporation has grown to
rank as one of the major firms in Japan.

To achieve this status, the company has through the years
diversified the range of its products and services to a remarkable
extent, until today, 19 plants and 16,000 employees produce over
1,000 different items, large and small.

All these products and all the services which accompany them,
however, are unified by one central commitment. KUBOTA makes
products which, taken on a national scale, are basic necessities.
Products which are indispensable, products intended to help
individuals and nations fulfill the potential inherent in their
environment. For KUBOTA is the Basic Necessities Giant.

This potential includes water supply, food from the soil and from
the sea, industrial development, architecture and construction, and
transportation.

Thousands of people depend on KUBOTA's know-how, technology,
experience and customer service. You too can depend on
KUBOTA.

KX91-3S2/U35-3S2

AO . I . 5 - 5 . 1 . AK

Abbreviations Description

LIST OF ABBREVIATION

American Petroleum Institute

American Society for Testing and Materials, USA

Committee for European Construction Equipment

German Institute for Standards, Federal Republic of Germany

European Standard

Falling Object Protective Structures

''Front'' means the front view towards the boom and dozer

High speed

International Standardization Organization

Japanese Industrial Standard

Volume (Liter)

Liter per minute

Low speed

Military Standards

Revolutions Per Minute

Roll-Over Protective Structures

Society of Automotive Engineers, USA

Two Pattern Selection System

Auto Idle

API

ASTM

CECE

DIN

EN

FOPS

FRONT

Hi

ISO

JIS

L

L/min

Lo

MIL

rpm

ROPS

SAE

TPSS

AI

GENERAL SYMBOLS

The instruments and operation elements have been marked with a series of symbols in order to simplify the operation of
excavator. These symbols are listed below with the respective descriptions.

Safety alert Symbol

Warning lamp ''Fuel level too low''

System lamp

Warning lamp ''Engine Oil pressure''

Warning lamp ''Battery charge''

Warning lamp ''Auto Idle (AI) Lamp''

Indicator lamp ''Glow''

Working light switch

Horn

Wiper/Washer switch

Diesel

Hydraulic fluid

Gear oil

Boom swing (left)

Boom swing (Right)

Dozer raise

Dozer lower

Operation direction of control lever

Operation direction of control lever

Read operator's manual

Engine stop control lamp

Grease

Fast

Slow

Excavator - Overhead movement toward the front

Excavator - Overhead movement toward the rear

Boom up

Boom down

Arm up

Arm crowd

Bucket crowd

Bucket dump

FOREWORD

You are now the proud owner of a KUBOTA Excavator. This excavator is a product
of KUBOTA quality engineering and manufacturing. It is made of fine materials and
under a rigid quality control system. It will give you long, satisfactory service. To
obtain the best use of your excavator, please read this manual carefully. It will help
you become familiar with the operation of the excavator and contains many helpful
hints about excavator maintenance. It is KUBOTA's policy to utilize as quickly as
possible every advance in our research. The immediate use of new techniques in
the manufacture of products may cause some small parts of this manual to be
outdated. KUBOTA distributors and dealers will have the most up-to-date
information. Please do not hesitate to consult with them.
Please note that there may be some differences between your actual machine and
the illustration in the instructions.

3

This symbol, the industry's ''Safety Alert Symbol'', is used throughout this manual
and on labels on the machine itself to warn of the possibility of personal injury.
Read these instructions carefully. It is essential that you read the instructions and
safety regulations before you attempt to assemble or use this unit.

3
3
3

IMPORTANT :

NOTE :

DANGER :

WARNING :

CAUTION :

Indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.

Indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.

Indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury.

Indicates that equipment or property damage could result if
instructions are not followed.

Gives helpful information.

SAFETY FIRST

CONTENTS

SAFE OPERATION ................................................................................................. 1

DEALER SERVICE...................................................................................................... 1

TECHNICAL DATA...................................................................................................... 2

DESCRIPTION OF MACHINE PARTS........................................................................ 3

INSTRUMENT PANEL AND CONTROL ELEMENTS................................................. 4

CHECKS BEFORE START ......................................................................................... 6

DAILY CHECKS....................................................................................................... 6

CAB TYPE MACHINES ........................................................................................... 6

Wiper/Washer Switch(CAB type only) ..............................................................................6

Interior Lamp(CAB type only) ...........................................................................................6

Heater Switch(CAB type).................................................................................................. 7

Opening/Closing of CAB Door(CAB type only)................................................................. 8

Opening/Closing of Front CAB Window(CAB type only) .................................................. 8

Working Light Switch ........................................................................................................9

Emergency Hammer(CAB type only)................................................................................9

OPERATION OF THE ENGINE................................................................................. 10

STARTING THE ENGINE ...................................................................................... 10

Display Selector Switch ..................................................................................................11

Charge Lamp..................................................................................................................12

Oil Lamp ......................................................................................................................... 12

Glow Lamp......................................................................................................................12

LCD Display for Normal Operation ................................................................................. 12

LCD Display for Warning ................................................................................................13

Warning Lamp ................................................................................................................14

Checkpoints after Starting the Engine ............................................................................ 14

STARTING THE ENGINE UNDER COLD CONDITIONS...................................... 15

STOPPING THE ENGINE...................................................................................... 15

Emergency Engine Stop Knob........................................................................................15

STARTING WITH AN AUXILIARY BATTERY ....................................................... 16

Observe Following Guidelines when Starting with an Auxiliary Battery..........................16

EXCAVATOR OPERATION ...................................................................................... 17

RUNNING-IN OF THE NEW EXCAVATOR........................................................... 17

Do not Work with Full Engine Rpm's or Full Loads during the First 50 Working Hours.. 17

Oil Change in the Run-in Stage......................................................................................17

Seat Belt .........................................................................................................................17

STARTING ............................................................................................................. 17

Operator's Seat...............................................................................................................17

Lock Lever ......................................................................................................................18

Working Light Switch ......................................................................................................19

Travel Buzzer..................................................................................................................19

DRIVING ................................................................................................................ 19

Drive Levers(Right,Left)..................................................................................................20

Travel Speed Switch.......................................................................................................21

CONTENTS

TURNS................................................................................................................... 22

Pivot Turn ....................................................................................................................... 22

Spin Turn ........................................................................................................................23

UP AND DOWNHILL DRIVING.............................................................................. 23

OPERATION OF THE DOZER .............................................................................. 24

TWO PATTERN SELECTION SYSTEM(TPSS) .................................................... 24

Pattern Change...............................................................................................................24

OPERATION OF THE BOOM................................................................................ 25

OPERATION OF THE ARM................................................................................... 26

OPERATION OF THE BUCKET ............................................................................ 26

UNIT SWING AND BOOM SWING OPERATION.................................................. 27

Unit Swing Operation......................................................................................................27

Boom Swing Operation................................................................................................... 27

SERVICE PORT OPERATION .............................................................................. 28

Service Port Operation ...................................................................................................28

One Way Flow Operation ...............................................................................................32

1-way or 2-way CIRCUIT SELECTION VALVE OPERATION ............................... 33

AUTO IDLE (AI) OPERATION ............................................................................... 34

IMPORTANT INFORMATION ON EXCAVATOR OPERATION ............................ 34

HOW TO RELEASE PRESSURE TRAPPED IN THE HYDRAULIC SYSTEM...... 35

TRANSPORTING THE EXCAVATOR ON A VEHICLE............................................. 36

LIFTING OF THE EXCAVATOR................................................................................ 38

MAINTENANCE......................................................................................................... 40

MAINTENANCE INTERVALS ................................................................................ 40

OPENING AND CLOSING OF PARTS.................................................................. 43

Opening and Closing of the Fuel Tank Cap....................................................................43

Opening/Closing of the Engine Hood .............................................................................43

Opening/Closing of the Side Hood .................................................................................43

Where to store the Tool and the Grease Gun.................................................................44

Where to keep Operators Manual...................................................................................44

DAILY CHECKS..................................................................................................... 45

Checking Coolant Level.................................................................................................. 45

Checking Fuel Level ....................................................................................................... 45

Checking Engine Oil Level..............................................................................................46

Checking Hydraulic Oil Level.......................................................................................... 46

Lubrication Points ........................................................................................................... 47

Checking Radiator and Oil Cooler ..................................................................................48

Checking Washer Liquid(only for CAB type) ..................................................................48

Checking and Cleaning Engine and Electrical Wiring.....................................................48

Washing Whole Machine................................................................................................48

REGULAR CHECKS AND MAINTENANCE WORK ................................................. 49

EVERY 50 SERVICE HOURS ............................................................................... 49

Draining Fuel Tank .........................................................................................................49

Draining Water Separator...............................................................................................49

Battery ............................................................................................................................ 49

Battery Charging.............................................................................................................50

Greasing Swing Bearing Teeth.......................................................................................51

EVERY 200 SERVICE HOURS ............................................................................. 51

Checking Fan Belt Tension.............................................................................................51

CONTENTS

Checking Radiator Hoses and Clamps...........................................................................51

Inspection and Cleaning Air Filter Element.....................................................................52

Air Filter Maintenance..................................................................................................... 53

Greasing Swing Bearing.................................................................................................53

Checking Fuel Line and Intake Air Line .......................................................................... 54

EVERY 250 SERVICE HOURS ............................................................................. 54

Changing Engine Oil(First Engine Oil Change after 50 Service Hours) ......................... 54

EVERY 500 SERVICE HOURS ............................................................................. 55

Replacing Engine Oil Filter(Replace the engine oil filter every 500 hours,

or every 1 year in the case that service hour is less than 500 hours).............................55

Drive unit Oil Change(First Oil Change at 100 hours) .................................................... 55

Replacing Fuel Filter Cartridge.......................................................................................56

Replacing Hydraulic Return Filter Element(first replacement after 250 service hours) .. 56

EVERY 1000 SERVICE HOURS ........................................................................... 57

Hydraulic Oil Check for Machines with Hydraulic Breakers............................................ 57

Hydraulic Oil Change(Including Replacing Suction Filter

and Breather Filter Element in Hydraulic Tank)..............................................................57

Replacing Hydraulic Pilot Filter Element.........................................................................58

EVERY 1000 SERVICE HOURS OR ONCE A YEAR ........................................... 58

Replacing Air Filter Element ........................................................................................... 58

EVERY 1500 SERVICE HOURS ........................................................................... 58

Checking Fuel Injection Nozzle(Injection Pressure) .......................................................58

EVERY 2000 SERVICE HOURS ........................................................................... 58

Changing Front Idler and Track Roller Oil ...................................................................... 58

Checking Alternator and Starter Motor ...........................................................................58

EVERY 3000 SERVICE HOURS ........................................................................... 59

Checking Injection Pump................................................................................................59

ANNUAL SERVICE................................................................................................ 59

Electrical Wiring and Fuses ............................................................................................ 59

BIENNIAL SERVICING .......................................................................................... 59

Replacing of Radiator Hoses..........................................................................................59

Changing Radiator Coolant ............................................................................................59

Replacing Fuel Hose ......................................................................................................60

Replacing Intake Air line.................................................................................................60

OTHER ADJUSTMENTS AND REPLACEMENTS.................................................... 61

PURGING FUEL SYSTEM .................................................................................... 61

ADJUSTMENT OF TRACKS ................................................................................. 61

Rubber Tracks ................................................................................................................61

Special Information when Using Rubber Tracks.............................................................62

Steel Tracks....................................................................................................................62

CHANGING THE BUCKET .................................................................................... 63

FUSES ................................................................................................................... 63

Replacing Fuses.............................................................................................................63

Fuse Capacities and Circuits..........................................................................................63

Auxiliary Electric .............................................................................................................64

Slow Blow Fuse ..............................................................................................................64

TROUBLESHOOTING............................................................................................... 65

KUBOTA I.C.S. NAVIGATION LIST OF MESSAGES ........................................... 67

OPERATION UNDER COLD WEATHER CONDITIONS .......................................... 69

CONTENTS

PREPARATION FOR OPERATION IN COLD WEATHER .................................... 69

PROCEDURE AFTER DONE WORK.................................................................... 69

LONG STORAGE ...................................................................................................... 70

RECOMMENDED OILS............................................................................................. 72

APPENDICES............................................................................................................ 73

MAIN DIMENSIONS .............................................................................................. 73

LIFTING CAPACITY .................................................................................................. 74

1SAFE OPERATION

SAFE OPERATION

The best insurance against accidents is to abide by the
safety regulations.

Read and understand this manual carefully before
operating the excavator.

Every user, however experienced, should carefully read
and understand this manual and those of the attachments
and accessories before taking the excavator into
operation. The owner is obliged to inform the operators of
these instructions in detail.
Keep this manual in the pocket under the seat.

1. Make yourself acquainted with the excavator and be
aware of its limits. Read the operating instructions
carefully before starting the excavator.

2. Obey the danger, warning and caution labels on the
machine.

3. For your safety, ROPS/FOPS (Roll-Over Protective
Structures, Falling Objects Protective Structures.) with
a seat belt is installed by KUBOTA. Always use the
seat belt when the machine is equipped with a ROPS/
FOPS.
Do not modify structural members of ROPS by
welding, drilling, bending, grinding or cutting, as this
may weaken the structure. If any component is
damaged, replace it. Do not attempt repairs. If ROPS
is loosened or removed for any reason, make sure all
parts are reinstalled correctly. Tighten mounting bolts
to proper torque.

4. The seat belt must be inspected regularly and
replaced if damaged.

5. Study control lever pattern A and pattern B. Then
choose the one which is most familiar. Familiarize
yourself with the pattern selected by operation slowly
at low engine speed.

6. Do not operate the excavator while under the influence
of alcohol, medication, controlled substances or while
fatigued.

7. Check the surroundings carefully before using the
excavator or when attachments are being attached.

A Pay attention to the overhead clearance with electric

wires.

A Check for pipes and buried cables before digging.
A Check for hidden holes, hindrances, soft underground,

and overhangs.

1. BEFORE OPERATION

(1) Seat belt

(1) Pattern selector lever (Two Pattern Selection System: TPSS)

SAFE OPERATION2

A During excavator use, do not allow any persons within

the working range.

8. Do not allow other persons to use the machine before
having informed him on the exact operation and work
instructions, and be assured that the operator's
manual has been read and completely understood.

9. Do not wear baggy, torn or oversized clothing when
working with the excavator. Clothing can get caught in
rotating parts or control elements which can cause
accidents or injuries. Wear adequate safety clothing,
e.g. safety helmet, safety shoes, eye protection, ear
protection, working gloves, etc., as necessary and as
prescribed by law or statutes.

10.Do not allow passengers to ride on any part of the
excavator at anytime. The operator must remain in the
excavator seat during operation.

11.Check mechanical parts for correct adjustments and
wear. Replace worn or damaged parts immediately.

12.Keep your excavator clean. Heavy soiling, grease,
dust and grass can cause fires, accidents or injuries.

13.Use only KUBOTA authorized attachments.

14.Before starting the excavator, be absolutely sure that
the excavator has been filled with fuel, lubricated,
greased and undergone all necessary maintenance.

15.Do not modify the excavator, otherwise it could lead to
unforeseen safety problems.

16.Make sure attachments, particularly those utilizing
quick attach systems, are securely mounted.

1. Get into and out of the machine safely. Always face the
machine. Always use handrails and available steps
and keep yourself well balanced. Do not hold any of
the control levers and switches. Do not jump on or off
the machine, whether stationary or in motion.

2. Start and control the excavator only from the
operator's seat. The driver should not lean out of his
seat when the engine is running.

3. Before starting the engine, make sure that lock levers
are in position "Lock" and all control levers and pedals
are in their neutral positions and the seat belt is
fastened correctly.

4. Make sure that the dozer blade is in front of you. (The
dozer must be raised.) If the levers are activated with
the dozer blade at the rear, the tracks will move in the
opposite direction of the drive levers.

5. Do not operate or idle engine in a non-ventilated area.
Carbon monoxide gas is colorless, odorless, and
deadly.

(1) Helmet
(2) Clothing fit for work
(3) Tight seams
(4) Good grip footwear
(5) Well fitting cuffs
(6) Working gloves

(7) Straw hat
(8) Towel
(9) Baggy trousers
(10) Loose cuffs of the shirt
(11) Baggy shirt
(12) Rubber sandals

2. STARTING OF THE EXCAVATOR

3SAFE OPERATION

6. Keep all safety equipment and covers in place.
Replace damaged or missing safety devices.

7. Precautions against tipping over. Keep away from
steep slopes and embankments. Do not swing the
bucket downhill. Lower the dozer during digging. Keep
the bucket as low as possible while driving uphill. Turn
slowly on slopes (at reduced speed). Do not place the
excavator near the edges of trenches and banks, as
the earth can give away due to the weight of the
excavator.

8. Watch out at all times for the area to which the
excavator is being moved.
Pay attention to any hindrances.

C Safety for children
Tragedy can occur if the operator is not alert to the
presence of children. Children generally are attracted to

machines and the work they do.

1. Never assume that children will remain where you last
saw them.

2. Keep children out of the work area and under the
watchful eye of another responsible adult.

3. Be alert and shut your machine down if children enter
the work area.

4. Never carry children on your machine. There is no safe
place for them to ride. They may fall off and be run
over or interfere with your control of the machine.

5. Never allow children to operate the machine even
under adult supervision.

6. Never allow children to play on the machine or on the
attachments.

7. Use extra caution when backing up. Look behind and
down to make sure the area clear before moving.

8. When parking your machine, if at all possible, park on
a firm, flat and level surface; if not, park across a slope.
Lower the bucket and dozer to the ground, remove the
key, place the control lock levers in the locked position
from the ignition and lock the cab door (if equipped),
before you leave.

Before leaving the machine,

A Park the excavator on a firm, flat and level surface.
A Lower the attachments and the dozer blade to the

ground.

A Stop the engine.
A Release pressure trapped in the hydraulic system.
A Lock all control levers.
A Remove the key.

3. AFTER OPERATION

(1) Lock lever for control lever (A) "Unlock"

(B) "Lock"

SAFE OPERATION4

1. Observe all regulations concerning the transport of
excavators on public roads.

2. Use adequately long and robust ramps when loading
on a vehicle. (for details see "TRANSPORTING THE
EXCAVATOR ON A VEHICLE")

3. Do not change the running direction and to avoid a
tipping over, do not try to swing the attachment
crosswise to the loading ramps.

4. Lower the attachment on the loading plane and
release the pressure from the hydraulic system.
Block the tracks with blocks and tie down the
excavator. After loading the excavator on the vehicle,
securely tie down the undercarriage of the excavator
using suitable chains, tensioners and approved
methods.

5. Avoid abrupt braking of the vehicle with the excavator
loaded. The excavator may shift causing on accident.

6. If the excavator is to tow another machine, make sure
the load is smaller than the strength of the hook, tow
chain or cable.

7. Do not use hooks on the roof of canopy or cabin for
lifting the excavator.

Before doing maintenance work on the excavator, place
the machine on even solid ground, lower the attachments
to the ground, stop the engine , release pressure trapped
in the hydraulic system and remove the key. When
dismantling hydraulic parts, make sure that the hydraulic
oil has cooled down sufficiently to avoid burns.
Start maintenance work carefully, e.g. loosen plug slowly
so that oil will not squirt out.

1. Before doing work on the engine, the exhaust system,
the radiator and the hydraulics, let the excavator cool
down sufficiently.

2. Turn off the engine at all times when filling with fuel.
Avoid spilling and over-filling of fuel.

3. Smoking is prohibited while refueling or handling the
battery! Keep sparks and fire away from the fuel tank
and battery. Flammable gases escape from the
battery, especially during charging.

4. Do not use or charge the refillable type battery if the
fluid level is below the LOWER (lower limit level) mark.
Otherwise, the battery component parts may be
prematurely deteriorated, which may shorten the
battery's service life or cause an explosion. Check the
fluid level regularly and add distilled water as required
so that the fluid level is between the UPPER and
LOWER levels.

5. Read and follow the directions "STARTING WITH AN
AUXILIARY BATTERY" in "OPERATION OF THE
ENGINE", when starting with an auxiliary battery.

6. Keep a first-aid box and a fire extinguisher at hand at
all times.

7. Do not open the radiator cap before the radiator has
cooled down sufficiently
First loosen the cap to the first stop and allow the
system enough time to release the remaining
pressure. Then loosen the cap completely.

8. To avoid short-circuiting the battery, always remove
the ground cable first and attach the plus cable first.

9. Leaking hydraulic fluid has enough pressure to
penetrate the skin and cause serious injuries.
Leakages from pin holes can be totally invisible. Do
not use hands for checking for leaks. Always use a
piece of wood or cardboard. It is strongly
recommended to use a face mask or eye protection.
Should injuries occur with leaking hydraulic fluid,
contact a doctor immediately. This fluid can cause
gangrene or serious allergic reactions.

4. SAFE LOADING AND TRANSPORT OF
THE EXCAVATOR

Max. drawbar pull at
coupling hook

70450 N (7183 kgf)

Max. vertical load at
coupling hook

7210 N (735 kgf)

5. MAINTENANCE

5SAFE OPERATION

10.To avoid environmental damage from acid and heavy
metals, do not throw the battery away.

11.Observe all laws and regulations concerning the
disposal of used oil, coolants, solvents, hydraulic
fluids, battery acids and batteries.

12.To avoid fire, do not heat the hydraulic components
(tanks, pipes, hoses, cylinders) before they have been
drained and washed.

13.Use a face mask or eye protection to protect the eyes
and respiratory system against dust and other foreign
particles.

14.Securely support excavator with stands or suitable
blocking before working underneath. For your safety,
do not work under any hydraulically supported
devices. They can settle, suddenly leak down, or be
accidentally lowered.

15.Do not dismantle the spring of the track tensioner. If
dismantling is necessary, contact your KUBOTA
dealer where the machine was purchased, or
competent service shop. The assembly must be done
according to the work shop manual of KUBOTA
(W.S.M.) for the product involved.

16.KUBOTA uses no parts which are lined with asbestos.
Do not use these kind of parts even if they are
available and can be installed.

SAFE OPERATION6

6. DANGER, WARNING AND CAUTION LABELS

7SAFE OPERATION

SAFE OPERATION8

9SAFE OPERATION

SAFE OPERATION10

11SAFE OPERATION

SAFE OPERATION12

1DEALER SERVICE

DEALER SERVICE

Your KUBOTA dealer is always ready to help so that your
excavator offers the best performance. After having
carefully read these instruction, you will realize that much
of the routine maintenance can be done by yourself. Your
KUBOTA dealer is responsible for servicing and the
delivery of spare parts. When ordering spare parts from
your KUBOTA dealer, always mention the serial number
of the excavator and the engine.
Note these numbers right away in the supplied lines.

Model Serial No.

Excavator

Engine

Dealer's name
(To be filled in through the owner)

(1) Serial No.

(1) Engine serial No.

2 TECHNICAL DATA

TECHNICAL DATA

A Above dimensions are based on the machine with rubber trucks.
A Specifications subject to change without notice.
D With unloaded digging bucket.
D Firm compacted soil.
D Operators must exercise extra caution and follow instructions in the operator's manual.
D Worse condition or heavier attachment to the above will decrease climbing angle.

KUBOTA EXCAVATOR

Model name KX91-3S2 U35-3S2

Type Canopy CAB Canopy CAB

Operating weight (including operator's) kg 3225 3325 3640 3750

Engine

Type Water cooled 4 cycle diesel engine with 3 cylinder

Model name

KUBOTA

D1703-M-E3-BH-US2

KUBOTA

D1703-M-E3-BH-US1

Total displacement cc 1647

Engine power SAE
J1955 gross

kW 22.1

Rated speed rpm 2250

Performance

Unit swing speed rpm 9.4 8.9

Travel speed

Fast km/h 4.8 4.6

Slow km/h 3.1 3.0

Ground pressure
(With operator)

kPa

(kgf/ )

31.8

(0.32)

32.8

(0.33)

32.7

(0.33)

33.7

(0.34)

Climbing angle % (deg) *36 (20)

Angle in case of
crossing slope

% (deg) *27 (15)

Dozer Width x Height mm 1550 x 335 1700 x 335

Boom swing angle

Left rad (deg) 1.40 (80) 1.22 (70)

Right rad (deg) 0.87 (50)

Pressure
connection
for
attachments

Max.displacement
(Theoretical)

L/min 63.0 60.0

Max. pressure

Mpa

(kgf/ )

23.5

(240)

24.5

(250)

Fuel tank capacity L 50 40

3DESCRIPTION OF MACHINE PARTS

DESCRIPTION OF MACHINE PARTS

DEPICTED CONTENTS

(1) Bucket cylinder
(2) Arm
(3) Bucket link 2 and 3
(4) Bucket link 1
(5) Bucket
(6) Boom cylinder
(7) Swing bracket
(8) Track
(9) Dozer blade

(10) Boom
(11) Arm cylinder
(12) Working light
(13) Canopy
(14) Drive sprocket
(15) Front idler
(16) Dozer cylinder
(17) Cabin

4 INSTRUMENT PANEL AND CONTROL ELEMENTS

INSTRUMENT PANEL AND CONTROL ELEMENTS

B Instrument Panel, Switches

DEPICTED CONTENTS

(1) Cup holder (U35-3S2)
(2) Service port switch
(3) Horn switch
(4) Breaker lock switch
(5) Travel speed switch
(6) Speed indicator light
(7) Starter switch
(8) LCD display
(9) Flow volume setting switch

(10) Switch for Auto idle control
(11) Heater switch (CAB type only)
(12) Emergency engine stop knob
(13) Cup holder (KX91-3S2)
(14) Wiper / Washer switch (CAB type only)
(15) Working Light switch
(16) Service port activation switch
(17) Display selector switch
(18) Warning lamp

5INSTRUMENT PANEL AND CONTROL ELEMENTS

B Control Pedals and Levers

D To prevent inadvertent machine movement, pull the lock lever.

DEPICTED CONTENTS

(1) Drive lever (left)
(2) Lock lever (left)*
(3) Control lever for front attachments (left)
(4) Drive pedal
(5) Drive lever (right)
(6) Lock lever (right) [Only Canopy type]*
(7) Control lever for front attachments (right)
(8) Dozer control lever
(9) Throttle potentiometer
(10) Boom swing pedal
(11) Service port activation switch

6 CHECKS BEFORE START

CHECKS BEFORE START

DAILY CHECKS

In order to avoid damage, it is important to check the
condition of the excavator before starting.

To avoid personal injury:
A Do maintenance work on the excavator only on

level ground with the engine off and the lock
lever in the "Lock" position.

Checks

Go around the excavator and check for visual damage
and wear.
Check coolant level. (See regular checkpoints in the
chapter on maintenance.)
Check fuel level.
Check engine oil level.
Check hydraulic fluid level.
Check air filter for clogging.
Check all control lamps, indicators, tachometer and hour
meter.
Check the light system.
Check the seat belt and the ROPS/FOPS safety device.
Check the condition of the safety and warning labels.
(See "DANGER, WARNING AND CAUTION LABELS" in
"SAFE OPERATION".)

CAB TYPE MACHINES

BWiper/Washer Switch(CAB type only)

Turn the starter switch to position "RUN" and push the
switch for the wiper and washer system; the wiper will
begin to move. A further push on the switch will activate
the washer system.
A Do not activate the switch if the tank for the cleaning

fluid is empty; the pump can be damaged.

A This can also be the case if the wiper is moved on a

dry window. In this case, make sure that cleaning fluid
is applied to the pane before activating the wiper.

A In frosty conditions, make sure that the wiper blade is

not frozen to the glass before switching-on. The motor
can be damaged if the wiper system is used under
such conditions.

BInterior Lamp(CAB type only)

To turn on the interior lamp, set the starter switch to the
"RUN" and then the interior lamp switch to the "ON"
positions, respectively.

(1) Wiper switch

(1) Interior lamp

7CHECKS BEFORE START

BHeater Switch(CAB type)

Turn the starter switch to position "RUN" and turn the
heater switch clockwise, the heater fan will be activated
and the CAB will start to warm up. The heater has two
positions - "Low" and "High" -.

A During the summer, turn the heater valve clockwise to

close the valve.

C Recirculation / Fresh Air Selection knob
A FRESH AIR: Set the knob to the position, and

fresh air will flow into the CAB. This is helpful when you
work in a dusty conditions or if the glass windows get
foggy.

A RECIRCULATION: Set the knob to the position,

and the in-CAB air will be recirculated.This is useful for
heating the CAB quickly or keeping it extra warm.

A When heating, do not keep the knob at the

"RECIRCULATION" position for a long time. The
windshield easily gets foggy.

A While working in a dusty conditions, keep the knob at

the "FRESH AIR" position. This increases the
pressure in the CAB, which helps prevent dust from
coming into the CAB.

(1) Heater switch (A) Pos. "High"

(B) Pos. "Low"
(C) Pos. "Off"

(1) Heater outlet

(1) Heater valve (A) Open

(B) Close

(1) Recirculation/
fresh air selection knob

"FRESH AIR"
"RECIRCULATION"

CHECKS BEFORE START8

BOpening/Closing of CAB Door(CAB type

only)

1. Unlock the CAB door and pull the knob. Open the CAB
door fully until fixed into place.

2. To close the CAB door, push the release lever down
and close the door.

3. When leaving the excavator, always lock the door.

BOpening/Closing of Front CAB

Window(CAB type only)

To avoid personal injury:
A Keep hands and feet away from the area

between front window and CAB frame.
Otherwise the operator risks serious injuries
by pinching or crushing.

A Other persons should stay away when opening

the window.

To open and close the front window, take the steps below.

1. Release the lock levers on the top of the front window.

2. Hold the top and bottom grips tightly with both hands.
Pull the top grip slightly upward and toward yourself to
let the windshield slide inward.

3. Pull the windshield all the way to the rubber at the back
of the CAB. Tighten up the lock levers.

(1) Door knob

(1) Release lever (A) Down

(1) Lock levers (2) Grip

9CHECKS BEFORE START

4. To close the window, take the reverse steps 3, 2 and 1.

BWorking Light Switch

To turn on the working light, set the starter switch to the
"RUN" position and press the working light switch.

BEmergency Hammer(CAB type only)

To avoid personal injury:
A When breaking the window pane, close your

eyes and cover them with an arm.

Emergency hammer is for breaking window pane to
escape urgently away from excavator as a result of
window rail locking mechanism failure.

(1) Lock lever

(1) Working light switch

(1) Emergency hammer

10 OPERATION OF THE ENGINE

OPERATION OF THE ENGINE

To avoid personal injury:
A Read "SAFE OPERATION" at the beginning of

this operator's manual.

A Obey the danger, warning and caution labels

on the excavator.

A To avoid the danger of exhaust fume

poisoning, do not operate the machine in a
closed building without proper ventilation.

A Always start the engine from the operator's

seat. Do not start the engine while standing
next to the excavator. Before starting the
engine, sound the horn to get the attention of
persons standing nearby.

A Do not use starting fluid or ether.
A In order not to overload the battery and starter, avoid

start-ups of more than 10 sec.

A When engine does not start in 10 sec., please wait 20

sec. or more, before attempting to restart.

STARTING THE ENGINE

To avoid personal injury:
A The operator should not depend solely on the

warning lamps, but should always conduct the
routine checks (see "MAINTENANCE").

Start the engine in the following manner:

1. Before starting the engine, make sure that all control
levers are in the neutral positions.

2. Pull the lock levers all the way back. (lock position)

3. Turn the throttle potentiometer towards the
symbol.

(1) Horn switch

(1) Drive lever (left)
(2) Drive lever (right)
(3) Attachment control lever (left)
(4) Attachment control lever (right)
(5) Lock lever (left)
(6) Lock lever (right) (Only Canopy type)

(1) Throttle potentiometer

11OPERATION OF THE ENGINE

4. Insert the key into the starter switch and turn it to the
position "RUN". The LCD display shows the figure
below. The glow lamp will light up while the engine is
preheated and will go out automatically after
preheating is finished.

5. Turn the key to the position "START" and release after
the engine has started.

6. Check if all warning lamps have gone out. Should a
warning lamp still be lit up, stop the engine then
remove the key and check for the cause.

BDisplay Selector Switch

Press the display selector switch while the engine is
running. The LCD meter display will change from one
indication mode to the other.
Change the two-mode display according to your jobs.

A With the starter key at the "STOP" position, press the

electronic meter's display selector switch or the
working light switch, and the LCD display shows the
hour meter, fuel gauge and water temperature gauge
for 10 seconds.

(1) Starter switch (A) "STOP"

(B) "RUN"
(C) "START"

(1) Fuel gauge
(2) Water temperature gauge
(3) Oil lamp

(4) Hour meter
(5) Charge lamp
(6) Glow lamp

(1) Display selector switch
(2) LCD meter display

(1) Fuel gauge
(2) Water temperature gauge
(3) Hour meter
(4) Engine tachometer

(A) "INDICATION MODE 1"
(B) "INDICATION MODE 2"

OPERATION OF THE ENGINE12

BCharge Lamp

This warning lamp lights up if the charging system fails
while the engine is running. When the starter switch is
turned "ON" with the engine off, the lamp lights up, and
when the engine gets started, the lamp goes out.

A If there is disconnection or failure in the charging

system when the key is turned to "RUN", the following

symbol will appear.

BOil Lamp

The engine oil pressure warning lamp lights up due to
failure of the lubricating system with the engine running.
When the starter switch is turned "ON" with the engine
off, this lamp lights up, and when the engine starts, the
lamp goes out. If the lamp stays on with the engine
running, stop the engine and check the engine oil level.

A If there is disconnection, failure or breakdown in the

lubricating system when the key is turned to "RUN",
the following symbol will appear.

BGlow Lamp

With the starter key at the "RUN" position, the engine's
preheat status is indicated.

A When the starter switch is turned to the "RUN"

position, the engine will be preheated for a given
period of time and the lamp will turn on.

A The above indication appears momentarily when the

engine is started, but it does not mean any trouble.
(This is because the oil charge sensor output becomes
unstable when the engine is started.)

A The symbol appears momentarily as the engine

starts. This is not an error.

BLCD Display for Normal Operation

C Fuel gauge

To avoid personal injury:

A Before adding fuel, be sure to stop the engine.
A Be sure to keep open flame away from the

machine. Otherwise a fire may be caused.

With the starter key at the "RUN" position, the fuel
remaining in the fuel tank is indicated in the block.

A If the fuel gauge indicator is near the "E" or the "FUEL"

message appears, add fuel as soon as possible. If the
indicator is near "E" and the machine runs on a slope,
the engine may run out of fuel and get interrupted.

C Fuel supply

The following functions are helpful when adding the fuel.
The fueling progress can be monitored by a buzzer sound.

Procedure

1. Press the work light switch or the display selector
switch on the meter with the key OFF. (Keep the key
at OFF.)

2. The message shown above appears.

3. Add fuel.

4. The buzzer sound interval changes according to the
amount fuel added. As the fuel amount becomes close
to full, the buzzer sound changes to continuous
beeping.

(1) Fuel gauge (A) "Empty"

(B) "Full"

13OPERATION OF THE ENGINE

To avoid personal injury:
A If the fuel is poured too fast, the buzzer may not

sound according to the fueling process.

A The moment when the fuel tank is nearly full,

the buzzer starts beeping.

A Look into the fuel tank when pouring the fuel.

Listen to the buzzer sound for a rough estimate
of the fill-up progress.

C Water Temperature Gauge

To avoid personal injury:
A Do not open the radiator cap during or just after

operation. Hot water may gush out and scald
you. Wait for the water to cool down before
opening the cap.

With the starter key at the "RUN" position, the cooling
water temperature is indicated. If the water temperature
indicator is near "H", take the steps below.

1. Discontinue the job.

2. Reduce engine rpm's to idle and keep it at idle for 5
minutes.

3. Stop the engine and check the following points (1)-(3).
(1) Low coolant level or leak
(2) Fan belt tension
(3) Mud or dust deposits on radiator

C Hour-meter

Indicates the total operating hours of the machine.

How the indicator works
A The meter advances one hour after an hour of

operation regardless of the engine rpm.

C Engine tachometer

Indicates the current rpm of the engine.

A The LCD display may be illegible when viewed from a

certain angle. This is not a display failure.

BLCD Display for Warning

C Remaining fuel warning

When the fuel level is very low, the lamp (yellow) starts
flashing and the following message appears in the
display.

C Battery charge warning

If the charging system fails, the lamp (red) starts
flashing and the following message appears in the
display.

(1) Water temperature gauge (A) "WATER TEMP LOW"

(B) "WATER TEMP HIGH"

OPERATION OF THE ENGINE14

C Engine oil pressure low warning

When the engine oil pressure drops too low, the lamp
(red) starts flashing and the following message appears in
the meter.
Immediately stop the engine and check the engine oil
level.

BWarning Lamp

A The warning lamp is used to indicate broken wire,

short-circuit, fuel shortage and other problems.

A Warnings and errors are displayed and an alarm

buzzer beeps.

A The warning lamp starts flashing in red if any trouble

occurs. If the system gets in warning signal, the
warning lamp starts flashing in yellow.

A Do not just look at the meter, but also carry out the

inspection and correction accordingly.

A Let your KUBOTA dealer inform you of details

concerning care and maintenance.

BCheckpoints after Starting the Engine

After starting the engine, but before starting operation,
check the following points:

1. Turn the throttle potentiometer down and let the
engine idle for approx. five minutes. This allows the
engine lubricant to warm up and penetrate every part
of the engine.

A This idling is usually called "Warm-up".

2. Once the engine has warmed up, check:
A the warning lamp "Engine oil pressure" has gone

out.

A the warning lamp "Battery charge" goes out when

engine speed is increased.

A the color of the exhaust is normal and no abnormal

noises or vibrations are heard or felt.

A no fluid is leaking from pipes or hoses.

C Should any following conditions occur, stop the

engine immediately.

A The engine rpm's increases or decreases suddenly.
A Sudden abnormal noises are heard.
A Exhaust is black.
A Warning lamp for engine oil lights up during operation.

A In these cases, the excavator must be checked and

serviced by your local the KUBOTA dealer.

(1) Warning lamp (red, yellow)
(2) LCD display

15OPERATION OF THE ENGINE

STARTING THE ENGINE UNDER COLD
CONDITIONS

To avoid personal injury:
A Make sure that the lock lever is in the lock

position during warm up.

Start the engine in the following manner;

1. Pull the lock levers all the way back (lock position).

2. Turn the starter switch to the position "RUN" (glow
position) and keep until the indicator lamp has gone
out.

3. Move the starter switch to the position "START"; to
crank and start engine.

4. Release the starter switch after the engine has started;
it will automatically return to the position "RUN ".

A Let the engine warm up after start-up.
A Let the engine warm up after start-up for approx. 10

minutes under no load conditions. If the hydraulic fluid
temperature is too low, the operations will be affected.
Do not operate the excavator under full load before the
engine has warmed up enough.

STOPPING THE ENGINE

To avoid personal injury or death:
A Do not keep the bucket or dozer in the lifted

position, as a person could accidentally touch
the levers and cause serious accidents.

BEmergency Engine Stop Knob

To avoid personal injury:
A Pull the engine stop knob up and hold it until

the engine stops in case of emergency.

The engine stops when the key is turned off. If the engine
does not stop, pull the engine stop knob up and hold it
until the engine stops. After the engine has stopped, be
sure to push the engine stop knob back in, or the engine
will not start next time.

A If the engine does not stop with the key, contact your

KUBOTA dealer.

1. After slowing the engine to idle, turn
the key to "STOP".

2. Remove the key.

(1) Emergency engine stop knob

OPERATION OF THE ENGINE16

STARTING WITH AN AUXILIARY BATTERY

To avoid personal injury:
A Battery gases can explode.

Do not smoke and keep sparks and flames
away.

A Do not start the engine with an auxiliary battery

if excavator battery is frozen.

A Do not connect the black jumper cable to the

negative (-) terminal of the excavator battery.

BObserve Following Guidelines when

Starting with an Auxiliary Battery

1. Bring the helping machine with the same battery
voltage as near as possible to the machine.
THE MACHINES MUST NOT COME IN CONTACT
WITH EACH OTHER.

2. Bring the levers and pedal of both machines in the
neutral position.

3. Wear eye protection and rubber gloves.

4. Ensure the vent caps are securely in place (if
equipped).

5. Connect the terminal of the red jumper cable with the
plus (+) terminal of the low battery and connect the
other end of the cable to the plus (+) terminal of the
auxiliary battery.

6. Connect the black negative cable to the minus (-)
terminal of the auxiliary battery.

7. Connect the other end of the black cable (coming from
the auxiliary battery) to the machine frame as far away
as possible from the low battery.

8. Start the engine of the helping machine and let it run
for a while. Start the machine with the low battery.

9. Disconnect the jumper cables in the reverse
sequence.

A This excavator has a negative (-) earthed 12 Volt

starting system.

A Only use the same voltage when using an auxiliary

battery.

A Using a higher voltage will cause serious damage to

the electrical system. When using an auxiliary battery,
only the compatible (same) voltage is permissible.

(1) Low battery
(2) Auxiliary battery
(3) Jumper cables

17EXCAVATOR OPERATION

EXCAVATOR OPERATION

RUNNING-IN OF THE NEW EXCAVATOR

The operation and care of the new excavator influences
its life span. Your new excavator has been carefully
checked and tested before leaving the factory. In spite of
this, all movable components must run-in during the first
50 work hours. Do not work with full rpm's and full loads
during this period. It is most important to run-in your
excavator properly in order to achieve its full performance
and longevity. During the running-in, the following points
should be adhered to in all cases.

BDo not Work with Full Engine Rpm's or

Full Loads during the First 50 Working
Hours

A Let the engine warm up sufficiently in the cold season.
A Do not let the engine rev-up more than necessary.

BOil Change in the Run-in Stage

The lubrication oil plays a specific and important role
during the run-in phase of the excavator. The numerous
movable parts are not yet run-in, so many fine metal
particles are generated and cause damage and shorten
the life of many components. Pay attention to the oil­change intervals and complete them sooner than later.
See "REGULAR CHECKS AND MAINTENANCE WORK"
section for more details on the oil-change intervals.

BSeat Belt

To avoid personal injury or death:
A Always use the seat belt with a ROPS/FOPS

protection structure. Adjust the seat to the
optimal position and buckle up.

STARTING

BOperator's Seat

To avoid personal injury:
A Make sure that the seat is completely secured

after each adjustment.

A Do not allow any person other than the driver to

ride on the excavator.

(1) Seat belt

1. Adjusting the Operator's Position.

(1) Backrest tilt adjust lever
(2) Arm rest angle adjust
knob
(3) Weight adjust lever
(4) Height adjust knob
(5) Weight and height
indicator
(6) Travel adjust lever
(7) Arm rest

(A) "UNLOCK"
(B) "TO INCREASE TENSION"
(C) "TO DECREASE TENSION"
(D) "TO INCREASE ANGLE"
(E) "TO DECREASE ANGLE"

EXCAVATOR OPERATION18

C Travel adjustment

Pull the travel adjust lever in the direction of [A] and
slide the seat backward or forward, as required. The
seat will lock in position when the lever is released.

C Weight adjustment

Turn the weight adjust lever to achieve the optimum
suspension setting.

C Tilt adjustment

Pull the backrest tilt adjust lever in the direction of [A]
and move the backrest to the desired angle.

C Height adjustment [KX91-3S2]

Pull up with your hands the seat pan in front of seat
belt to the desired height of the three available
positions.
Once it has reached the highest level, it will return to
the lowest level.

C Arm rest

Arm rest may be set at upright position if desired.

C Arm rest angle adjustment

Turn the arm rest angle adjust knob to the desired
angle.

BLock Lever

To avoid personal injury:
A To avoid injuries, check safety features all

around the excavator.

A With the lock lever pulled down, the engine

fails to start.

If you try to start the engine with the key with the lock lever
down, the following message appears momentarily on the
meter display.

(1) Backrest tilt adjust knob
(2) Weight adjust lever
(3) Travel adjust lever
(4) Arm rest
(5) Seat lock lever

(A) "UNLOCK"
(B) "TO INCREASE TENSION"
(C) "TO DECREASE TENSION"
(D) "TO INCREASE ANGLE"
(E) "TO DECREASE ANGLE"

2. After starting the engine, bring the
lock levers into the "Unlock" position
to use drive lever or control lever for
front attachments.

(1) Lock levers (A) "Unlock"

19EXCAVATOR OPERATION

BWorking Light Switch

When the starter switch is in position "RUN", the light(s)
can be switched on by pressing the switch.

C Night operation

To avoid personal injury:
A Visibility is reduced in darkness, therefore the

work light alone may not be enough. In which
case, prepare additional stationary artificial
lighting, observe safety rules as well as special
regulations for night work.

BTravel Buzzer

When you handle the drive levers, the buzzer sounds at
the same time or before the excavator starts to run.

DRIVING

To avoid personal injury or death:
A Before starting the engine, make sure that no

one is near the excavator.

A Before operating the excavator, check the track

direction. (Front idler and dozer blade to the
front of the excavator).

A Use extra caution when traveling across a

slope or working sideways on a slope.

A Recommended technique for working on a

slope.

(1) Working light switch

EXCAVATOR OPERATION20

1. Adjust the engine speed from idling to an intermediate
speed.

2. Unlock the lock levers and pull in the bucket and hold
the bucket about 20 to 40cm above the ground.

3. Activate the dozer control lever to raise the dozer.

BDrive Levers(Right,Left)

To avoid personal injury or death:
A If the swing frame has been turn 180deg, i.e. the

dozer in relation to the operator's seat is
"behind", then the travel direction is opposite
to the drive direction of the levers (when
activating the drive lever forwards, the
machine, in relation to the operator's seat, will
move backwards).

Pushing the drive lever forwards, moves the excavator
forwards, and vice-versa. The front of the excavator is the
side where the dozer is located; the drive sprocket is in the
rear of the excavator.

(1) Lock lever (A) "Unlock"

(A) 20 to 40 cm

(1) Dozer control lever (A) "Raise"

(B) "Lower"

(A) "Raise"
(B) "Lower"

21EXCAVATOR OPERATION

BTravel Speed Switch

To avoid personal injury:
A When activating the travel speed switch, it

must be pushed down completely.

Travel speed will increase when this switch is pushed
down.
Switching the dual travel speed:

1. Press the travel speed switch. The buzzer beeps and
the travel speed changes from first speed to second.
The symbol lights up.

2. Press the travel speed switch again, and the buzzer
beeps and the travel speed changes from second
speed to first. The symbol light goes out.

A Each time the travel speed switch is pressed, the

travel speed is switched between first and second.

A Do not activate the travel speed switch when there is

increased drive resistance (e.g. driving on inclines or
on uneven grounds).

A If the tracks are clogged with sand or gravel while

working on soft ground, lift up both tracks with the help
of the boom, arm, dozer blade and bucket and let the
track rotate to remove the sand and gravel.

(A) "Forward"
(B) "Backward"
(C) "Straight"

(1) Drive lever (left)
(2) Drive lever (right)

(A) "Forward"
(B) "Backward"

(1) Travel speed switch
(2) Speed indicator light

EXCAVATOR OPERATION22

To avoid serious injury or death:
A Do not work under the machine in this

condition.

TURNS

To avoid personal injury:
A Do not change direction on steep slopes, or the

excavator could tip over.

A Before changing direction, beware of people in

the work area.

BPivot Turn

A Movement as illustrated is done with the dozer blade

in front of the operator.

When the dozer is in the back, the steering direction is
reversed.
(For example, push the left drive lever forward the
excavator turns right; the left track, seen from the
operator, will move backward from the operator.)

C Change of Direction while Travelling

1. While travelling forwards, bring the left drive lever into
the neutral position;
the excavator will turn to the left.

2. While travelling backwards, bring the left drive lever
into the neutral position;
the excavator will turn to the right.

C Change of Direction while Stationary

1. Push the left drive lever forward;
the excavator will turn to the right.

2. Pull the left drive lever backward;
the excavator will turn to the left.

(A) "Rotate to remove sand
and gravel"

(A) "Travelling forward" (N) "Neutral position"

(B) "Travelling backward" (N) "Neutral position"

23EXCAVATOR OPERATION

BSpin Turn

When both drive levers are activated in the opposite
directions, both tracks will rotate with the same speed but
in opposite directions. The center of rotation is the center
of the excavator.

UP AND DOWNHILL DRIVING

To avoid personal injury:
A When traveling up or down a slope, use extra

caution and follow the instructions below.

While traveling uphill, keep the lower edge of the bucket
approx. 20 to 40cm above the ground. Although the
KUBOTA excavator will not slip easily because of the
tracks, it is safer to let the bucket slide over the ground
while traveling downhill. Always choose slow speed for
uphill and downhill traveling.

[UPHILL TRAVELING]

[DOWNHILL TRAVELING]

(A) "Left spin turn"

(B) "Right spin turn"

(A) 20 to 40 cm

EXCAVATOR OPERATION24

OPERATION OF THE DOZER

1. To raise the dozer, pull back the control lever. Pushing
the control lever forwards, lowers the dozer.

2. While undertaking earth moving work, control both
drive levers with the left hand and the dozer control
lever with the right hand.

TWO PATTERN SELECTION
SYSTEM(TPSS)

To avoid personal injury:
A Study control lever pattern A and pattern B.

Then choose the one which is most familiar

A Position the pattern selector lever (located on

the right side of operator's seat) in either the
lower position (pattern A) or the upper position
(pattern B).

A Engage the lock lever to prevent accidental

pattern change.

A Familiarize yourself with the pattern selected

by operating slowly.

BPattern Change

1. Loosen the lock lever knob and slide it to the direction
(a), and position the pattern selector lever to the
desired position.

2. Slide the lock lever knob to the direction (b) and tighten
it.

(1) Dozer control lever (A) "Raise"

(B) "Lower"

(A) "Raise" (B) "Lower"

(1) Pattern selector lever (Two Pattern Selection System: TPSS)
(2) Lock lever knob

25EXCAVATOR OPERATION

OPERATION OF THE BOOM

To raise the boom, pull the attachment control lever back.
The boom is equipped with a cushion cylinder which helps
prevent excavated material in the bucket from falling out.
Low hydraulic oil temperature, (e.g. after starting the
engine in cold weather) the cushioning function will be
effected for a short period of time (approx. 3 to 5
seconds). This condition results from the viscosity of the
hydraulic oil and is not a sign of malfunction.
The cushion cylinder will operate normally as the oil
warms up.

A When lowering the boom, make sure that it does not

hit the dozer and that the bucket teeth do not touch the
dozer.

Lever Position Pattern A Pattern B

Attachment
Control Lever
(Left)

A
B
C
D

Boom down
Boom up
Swing left
Swing right

Arm up
Arm crowd
Swing left
Swing right

Attachment
Control Lever
(Right)

1
2
3
4

Arm up
Arm crowd
Bucket crowd
Bucket dump

Boom down
Boom up
Bucket crowd
Bucket dump

EXCAVATOR OPERATION26

OPERATION OF THE ARM

Pull back the attachment control lever and the arm will be
pulled in. To move the arm out, push the control lever
towards the front.

A When pulling in the arm, the movement may stop for a

short moment when the arm is in its vertical position.
This is caused by the combined load of the arm and
bucket moving the cylinder piston away from the
hydraulic flow causing a delay in the cylinder action,
until the flow catches up with cylinder piston. This is a
characteristic of the hydraulic system and is no sign of
a malfunction.

OPERATION OF THE BUCKET

To dig using the bucket, move the right attachment control
lever from the neutral position, left. Moving the control
lever right, moves the bucket outwards and empties its
contents.

27EXCAVATOR OPERATION

UNIT SWING AND BOOM SWING
OPERATION

To avoid personal injury:
A When working in groups, always let the others

know what you are going to do before you do it.

A Keep others away from the machine working

area.

A Be sure to lock the boom swing pedal when the

boom swing function is not used.

BUnit Swing Operation

1. Move the control lever to the left and the upper
structure will turn to the left.

2. Move the control lever to the right and the upper
structure will turn to the right.

BBoom Swing Operation

1. Tilt the pedal rearward.

2. Step on the left side of the pedal to swing the boom to
the left.

3. Step on the right side of the pedal to swing the boom
to the right.

A Do not operate the left attachment control lever

abruptly from right to left (or vice versa). Because the
low of inertia cause high impact load on the swing gear
and the swing motor, shortening the life of the
excavator.

(1) Boom swing operation pedal

28 EXCAVATOR OPERATION

SERVICE PORT OPERATION

To avoid personal injury:

A In the limited flow volume mode, be careful not to get the arm relieved. The service port will otherwise get fully

open.

A When the lock lever is raised, the service port activation switch is off.
A Let the engine warm up after start-up for approx. 10 minutes under no load conditions.

BService Port Operation

This knob is used to operate hydraulic attachment such as breakers.

29EXCAVATOR OPERATION

C Usual settings

A Action mode of service port operation

It is possible to select from four action modes of the service port operation by pushing the service port activation switch.
Each time the service port activation switch is pushed, the action mode changes from 1 through 4.

A When turning the starter key to the "RUN" position, the action mode will return to the last action mode used.

C Initial setting of limited service port flow volume (Make this setting first.)

30 EXCAVATOR OPERATION

A Setting of limited flow volume

Max. flow volume right and left can be adjusted in 15 stages independently.

31EXCAVATOR OPERATION

A Service Port Max. Flow Volume

Max. Flow Volume

(Theoretical

L /min.)

KX91-3S2 63.0

U35-3S2 60.0

Max. Pressure

MPa

(kgf/cm )

KX91-3S2 23.5 (240)

U35-3S2 24.5 (250)

32 EXCAVATOR OPERATION

A When the service port is not used for a long period, dirt particles can settle in the lower part of the service port lines.

When the plugs on the service port lines are removed to connect attachments, drain approx. 100 cc (3.4 oz) of oil per
side before making connections.
For breaker choices, contact your dealer.

A Do not change the engine rpm using the limited flow volume setting. The service port speed will be otherwise lower, by

which the attachment may get interrupted.
In making the limited flow volume setting, find an optimum setting while varying the engine rpm.

A Suppose that the same attachment is mounted on another machine. Even if the same limit setting is made, the same

speed cannot be achieved. Make an optimum setting on each machine.

BOne Way Flow Operation

33EXCAVATOR OPERATION

1-way or 2-way CIRCUIT SELECTION
VALVE OPERATION

A selection valve which selects 1-way or 2-way circuit of
service port has been installed on the hydraulic tank.

1. When equipment which needs a 1-way circuit will be
used, position the arrow, by using the supplied lever,
on the axis of the selection valve to the 1-way circuit
position , to reduce the back pressure.

2. When equipment which needs a 2-way circuit will be
used, position the arrow on the axis of the selection
valve to the 2-way circuit position.

To avoid personal injury:
A Stop the engine before removing/changing the

equipment.

A Release pressure in the hydraulic system

before removing/chaging the equipment. (See
"HOW TO RELEASE PRESSURE TRAPPED IN
THE HYDRAULIC SYSTEM".)

A Position the selection valve to the correct

position (either 1-way or 2-way circuit
selection) before mounting the equipment.

A Always select the correct valve position (1-way

or 2-way circuit selection) to avoid sudden
movement of the equipment.

A Leaving the selection valve to 1-way circuit selection

and attaching 2-way circuit equipment may cause the
equipment to move (drop) suddenly due to its own
weight, as the tank line remains open, even with the
engine off.

NOTE:

A 1-way circuit..... HAMMER etc.

A 2-way circuit..... THUMB, TILT BUCKET,

AUGER, GRAPPLE etc.

EXCAVATOR OPERATION34

AUTO IDLE (AI) OPERATION

1. Throttle Potentiometer
With this potentiometer the operator can adjust the
engine speed when the Auto Idle control is activated.

2. Switch for Auto Idle (AI) Control
With this switch the Auto Idle control is turned on or off.
The Auto Idle control allows the engine speed to drop
to the engine speed preselected with the
potentiometer after about 4 seconds. If the control
activated, the engine speed rises immediately to the
preset rpm. If the Auto Idle is not activated the throttle
potentiometer can be utilized to control engine speed
similar way to a conventional throttle control lever.

A It is possible that the Auto Idle may not function until

hydraulic oil warms up in the cold weather. Therefore
it is not recommended that the Auto Idle be activated
until the machine is completely warmed up.

A Before operating the control lever, check the Auto Idle

Indicator Lamp.

A When operating in confined spaces or when loading

onto a vehicle, turn the Auto Idle switch off (Light off).
This is to prevent unwanted engine speed increases
when control levers are activated.

A The Auto Idle control, when selected by a switch,

provides the operator with a way to control engine
speed without a Throttle Potentiometer, simply by not
activating any control levers for about four seconds
after stopping work, and then to simply restore a
preset (by potentiometer) engine speed by activating
any control lever to return to work.

A The purpose of system is to reduce fuel consumption,

noise and operator fatigue.

IMPORTANT INFORMATION ON
EXCAVATOR OPERATION

A Do not try to crush concrete or boulders using side

swings with the bucket. Also avoid using side sweeps
of the bucket to move earth piles.

A Under all circumstances avoid the following

operations:
A Excavation using the gravitational impact of the

machine.

A Compacting of gravel or soil using the dropping

action of the bucket.

A Excavation using the traveling power of the

machine.

A Do not try to drop or shake off soil adhering to the

bucket in the manner given in the points below. This
can cause damage to the machine.
Adhering soil can be shaken off when the bucket is
being emptied by moving the bucket out to the
maximum stroke of the cylinder. Should this not
suffice, swing out the arm as far as possible and
operate the bucket back and forth.

A Do not hit the dozer with the boom cylinder!

Make sure that the boom cylinder does not hit the
dozer when doing deep excavation. If necessary
swing around so that the dozer is in the back of the
machine.

A Pay attention when pulling in the bucket!

When pulling in the bucket (for driving or
transportation) avoid hitting the dozer.

A Avoid collisions!

When moving the excavator, pay attention that the
dozer does not collide with obstructions such as
boulders etc..
Such collisions shorten the life of the dozer and the
cylinder substantially.

A Support the machine correctly!

When stabilizing the machine with the dozer, lower the
dozer to engage the full width on the ground.

A If the water or mud level reaches higher than the top of

the tracks, the swivel bearing, swivel motor gear and
ring gear may be exposed to mud, water and other
foreign objects.
The excavator must be properly pressure washed
after each use.
A Thoroughly clean the area around the swivel

bearing, swivel motor gear and ring gear to remove
foreign objects.

A Inspect the swivel motor oil sump (if equipped) for

water contamination. If water is present, refer to
operator's manual for lubricant replacement
procedure.

A Refer to operator's manual for proper swivel

bearing, swivel motor gear and ring gear
lubrication procedures.

A Reinstall any protective covering if removed

earlier.

(1) Throttle potentiometer
(2) Switch for Auto Idle control

35EXCAVATOR OPERATION

HOW TO RELEASE PRESSURE TRAPPED
IN THE HYDRAULIC SYSTEM

A Lower the attachments and the dozer blade to the

ground.

A Turn the key to "STOP" position and shut off the

engine.

A After stopping the engine, turn the key to "RUN"

position.

A Release pressure in the hydraulic system by operating

levers with lever lock pulled down.

36 TRANSPORTING THE EXCAVATOR ON A VEHICLE

TRANSPORTING THE EXCAVATOR ON A VEHICLE

To avoid personal injury or death:
A No directional changes should be made when

the excavator is on the ramp. Should a change
of direction be necessary, drive off the ramp
completely and make the turn.

A When driving forwards or backwards onto the

vehicle, or when swinging the upper body,
make sure that neither the CAB or the gates of
the vehicle will be damaged.

A When the excavator reaches the point between

the ramps and the bed, halt and then move very
slowly until the excavator reaches the
horizontal position.

A Move the excavator onto the vehicle only with

the arm completely pulled in. Otherwise the
CAB of the vehicle could be damaged when
swinging around the upper body.

A Do not jack up the machine using its boom to

load or unload the excavator from the vehicle.
Doing this is dangerous.

A Make sure the ramp are of sufficient capacity

and securely connected to the vehicle to safety
support the machine throughout the loading /
unloading operation.

B Transporting on a truck

To avoid personal injury or death:
A After loading the machine on the truck, lower

the bucket and dozer onto the truck bed. Lock
the swing frame with the swing lock pin.

Prepare a platform to load or unload the excavator.
Take following steps when using ramps.

1. Apply the parking brakes of the vehicle, and block the
drive wheels from both sides.

2. Use mounting brackets secure the ramp properly.
Connect the ramps directly to the bed.

3. For additional safety, use blocks or supports under the
ramps and the bed.

37TRANSPORTING THE EXCAVATOR ON A VEHICLE

4. Completely align the ramps and the tracks and then
drive the excavator slowly up the ramps with the dozer
in the front. After ensuring that the tracks are
completely on the bed, swing the upper body around
to the back of the vehicle.

5. Block the tracks and chain down the excavator with
suitable chains and approved method (check
appropriate state regulation).

6. Before unloading, raise the dozer and bucket from the
bed.

38 LIFTING OF THE EXCAVATOR

LIFTING OF THE EXCAVATOR

To avoid serious injury or death:
A The correct instructions for safe handling are

described here. Read these instructions
carefully before moving the machine. Make
sure that the operating personnel read the
operator's manual carefully.

B Basics when Lifting with Cables or Straps

1. The lifting and crane operation is to be undertaken
according to the safe operation guidelines described.

2. The equipment used for lifting mentioned in these
instructions are only given as reference, the standards
concerning strength, control and other details are
based on the respective applicable guidelines.

B Safety Aspects when Lifting with Cables or Straps

Abide by following steps when lifting:

1. Do not lift loads that exceed the maximum load
capacity of the crane.

2. Choose correct equipment suitable to the weight, size
and form of the load.

3. First assess the center of gravity of the load, position
the hook directly over the load and lift the load so that
the center of gravity of the load is as low as possible.

4. The steel cables or straps must be fixed in the middle
of the hook.

5. The load must be lifted vertically from the ground.

6. Do not enter the working area under suspended loads
and do not move the load over people. The load must
only be moved in an area where the balance can be
easily maintained.

B Lifting Procedure for the Excavator

To avoid personal injury or death:
A Do not use the hooks on the roof of canopy and

CAB for lifting the excavator.

C General guidelines for lifting

1. Lifting position. (see the following illustration.)
(1) Pull in the boom completely towards the CAB.
(2) Pull in the arm completely.
(3) Pull in the bucket completely.
(4) Adjust the swing angle to the center. (to bring the

boom in a position parallel to the machine frame)

(5) Swing frame so that dozer blade is to the rear and

frame is parallel with tracks.

(6) Raise the dozer blade fully.

2. Attaching the steel cables or straps.
(1) Always hook the excavator at three points. (one

on the boom and left and right of the dozer)

(2) Always use a shackle on each lifting hole when

attaching the cables or straps.

(3) Using protective material at all places where the

cables or straps contact the machine.

(4) Keep the angle between the front and rear cables

or straps within 60 (1.05 rad.).

To avoid personal injury or death:
A Never lift the excavator by hooking the hole of

the boom only.

39LIFTING OF THE EXCAVATOR

3. Tackle
The weights of the excavators and the recommended
tackle for lifting these loads are mentioned in the
following table. Choose components having enough
strength.

*Excavator Weight: With CAB, steel tracks, and long
arm.
Steel cable: 6 x 24

4. Lifting
(1) Lift slowly and safely
(2) Do not enter the excavator area when lifting.
(3) Lift the excavator horizontally. (Modify wire

connections according to needs)

Maximum strength
for example : (JIS G 35 25) - "6 x24"

1. Boom side
Hook in the steel cable with a shackle into the lifting
hole.

2. Dozer side
Hook in the steel cable with a shackle into the lifting
hole around the CAB or canopy.

3. Lifting

KX91-3S2 U35-3S2

Excavator
Weight*

kg 3330 3750

Load / Cable

N

(kgf)

12560
(1286)

11174

(1139)

Minimum
Cable
Diameter
(Safety
factor=6)

mm

14

(9/16)

or more

14

(9/16)

or more

Diameter zinc-plated not zinc-plated

10 mm

(3/8)

KN

(kgf)

45.8

(4670)

49.3

(5027)

12.5 mm
(1/2)

KN

(kgf)

71.5

(7291)

77

(7852)

14 mm

(9/16)

KN

(kgf)

89.7

(9147)

96.6

(9850)

16 mm

(5/8)

KN

(kgf)

117

(11931)

126

(12848)

18 mm
(45/64)

KN

(kgf)

148

(15092)

160

(16315)

(1) Steel cable
(2) Shackle

(1) Steel cable
(2) Shackle

(1) Protective material

40 MAINTENANCE

MAINTENANCE

MAINTENANCE INTERVALS

No. Check points Measures

Hour meter indicator

Interval

Ref.

page

50 100 150 200 250 300 350 400 450

1 Coolant

check Daily check 45

change every 2 years 59

2 Fuel check Daily check 45

3 Engine oil

check Daily check 46

change

every 250 hrs

or every 1 year

54

4 Hydraulic oil

check Daily check 46

change every 1000 hrs 57 *1

5 Lubrication points - Daily check 47

6 Radiator and oil cooler check Daily check 48

7 Washer liquid (CAB type) check Daily check 48

8 Engine and electrical wiring check Daily check 48

9 Fuel tank, Water separator drain every 50 hrs 49, 49

10 Battery condition check every 50 hrs 49

11 Greasing swing bearing teeth - every 50 hrs 51

12 Fan belt tension adjust every 200 hrs 51

13 Radiator hoses and clamps

check every 200 hrs 51

replace every 2 years 59

14 Air filter element

Outer element

clean every 200 hrs 52 *2

@

replace every 1000 hrs 58 *2

Inner element replace every 1000 hrs 58 *2

15 Greasing swing ball bearings - every 200 hrs 53

16 Fuel filter cartridge replace every 500 hrs 56 @

17 Engine oil filter replace

every 500 hrs

or every 1 year

55

18 Drive unit oil change every 500 hrs 55

19 Hydraulic return filter element replace every 500 hrs 56

20 Hydraulic breather filter element replace every 1000 hrs 57

21 Hydraulic suction filter element replace every 1000 hrs 57

22 Filter in the pilot hydraulic system replace every 1000 hrs 58

23

Fuel injection nozzle injection
pressure

check every 1500 hrs 58 *4 @

24 Front idler and track roller oil change every 2000 hrs 58

25 Alternator and starter motor check every 2000 hrs 58

26 Injection pump check every 3000 hrs 59 *4 @

27 Radiator system rinse every 2 years 59

28 Fuel line and Intake air line

check every 200 hrs 54

@

replace every 2 years 60 *3

D 500 thru 1000 continued to the following table.

41MAINTENANCE

D The engine oil is gradually consumed and reduced with engine operation. The consumption depends on the type of job

and the model of engine. Before operation, make sure that the oil level is between the upper and lower limits of the oil
level gauge. Add oil as required. To avoid a shortened service life or burn-out of the engine, use a Kubota-specified oil
and genuine Kubota filter. Keep their specified replacement intervals in mind.

No. Check points Measures

Hour meter indicator

Interval

Ref.

page

500 550 600 650 700 750 800 1000

1 Coolant

check Daily check 45

change every 2 years 59

2 Fuel check Daily check 45

3 Engine oil

check Daily check 46

change

every 250 hrs

or every 1 year

54

4 Hydraulic oil

check Daily check 46

change every 1000 hrs 57 *1

5 Lubrication points - Daily check 47

6 Radiator and oil cooler check Daily check 48

7 Washer liquid (CAB type) check Daily check 48

8 Engine and electrical wiring check Daily check 48

9 Fuel tank, Water separator drain every 50 hrs 49, 49

10 Battery condition check every 50 hrs 49

11 Greasing swing bearing teeth - every 50 hrs 51

12 Fan belt tension adjust every 200 hrs 51

13 Radiator hoses and clamps

check every 200 hrs 51

replace every 2 years 59

14 Air filter element

Outer element

clean every 200 hrs 52 *2

@

replace every 1000 hrs 58 *2

Inner element replace every 1000 hrs 58 *2

15 Greasing swing ball bearings - every 200 hrs 53

16 Fuel filter cartridge replace every 500 hrs 56 @

17 Engine oil filter replace

every 500 hrs

or every 1 year

55

18 Drive unit oil change every 500 hrs 55

19 Hydraulic return filter element replace every 500 hrs 56

20 Hydraulic breather filter element replace every 1000 hrs 57

21 Hydraulic suction filter element replace every 1000 hrs 57

22 Filter in the pilot hydraulic system replace every 1000 hrs 58

23

Fuel injection nozzle injection
pressure

check every 1500 hrs 58 *4 @

24 Front idler and track roller oil change every 2000 hrs 58

25 Alternator and starter motor check every 2000 hrs 58

26 Injection pump check every 3000 hrs 59 *4 @

27 Radiator system rinse every 2 years 59

28 Fuel line and Intake air line

check every 200 hrs 54

@

replace every 2 years 60 *3

42 MAINTENANCE

First operation
*1 When using a hydraulic breaker, change hydraulic oil and return filter according to the table on "Hydraulic Oil Change

(Including Exchange of the Suction Filter in the Hydraulic Tank) under "EVERY 1000 SERVICE HOURS" in the chapter
"REGULAR CHECKS AND MAINTENANCE WORK".
*2 Clean and replace the air filter more frequently if used under dusty conditions. When the filter is very dirty from dusty
conditions, replace the filter.
*3 Replace only if necessary.
*4 Consult your local KUBOTA Dealer for this service.
A The items listed above (@ marked) are registered as emission related critical parts by KUBOTA in the U.S.EPA non-

road emission regulation. As the engine owner, you are responsible for the performance of the required
maintenance on the engine according to the above instruction. Please see the Warranty Statement in detail.

43MAINTENANCE

OPENING AND CLOSING OF PARTS

BOpening and Closing of the Fuel Tank Cap

1. Open the tank cap cover, insert the starter key and
turn counterclockwise. Then turn the tank cap counter­clockwise to open.

2. To close the tank cap, turn clockwise and turn
clockwise the starter key. Then close the tank cap
cover.

BOpening/Closing of the Engine Hood

To avoid personal injury:
A Do not open the engine hood with the engine

running unless in an emergency.

A Do not touch the exhaust muffler or the

exhaust pipe; serious burns can occur.

Insert the key into the key hole and turn it clockwise to
open the hood. To close it, lower the bonnet and hold it
down tightly. Turn the key counter-clockwise to lock the
hood.

BOpening/Closing of the Side Hood

1. Raise the catch lever to unlock the side hood.

2. Push the side hood all the way forward, and it will be
held by a restraint cable.

3. For closing pull the side hood all the way back, and pull
down the catch lever to lock the side hood.

(1) Starter key
(2) Fuel tank cap
(3) Tank cap cover

(1) Fuel tank cap

(1) Key (A) Unlock

(B) Lock

(1) Catch lever
(2) Side hood
(3) Rear Hood

MAINTENANCE44

BWhere to store the Tool and the Grease

Gun

[KX91-3S2]

1. Remove the mat and the cover of left side step.

2. Store the tools or grease gun in the storage box.

[U35-3S2]

1. Pull the seat lock lever and tilt over the seat forward.

2. Store the tools in the storage box.

To avoid personal injury:
A Stop the engine and remove the key before

tilting the seat.

BWhere to keep Operators Manual

(1) Box for storage

(1) Grease gun (Option)

(1) Tool box

(1) Operator's manual storage

(1) Operator's manual storage

45MAINTENANCE

DAILY CHECKS

For your own safety and to assure the long life of your
machine, a careful check should be made before each
operation.

BChecking Coolant Level

To avoid personal injury:

A Move the excavator to even ground.
A Make sure that the engine is turned off.
A Do not open the radiator cap right after the

engine has been stopped; Serious burns can
occur from contact with escaping hot coolant
fluid.

A Check the coolant level in the reserve tank only

after the engine has cooled down.

A Remove the radiator cap only if absolutely

necessary.

1. Check to see that the coolant level is between the
"FULL" and "LOW" marks of a reserve tank.

2. When the coolant level drops due to evaporation, add
water only up to the full level.
In case of leakage, add anti-freeze and water in the

specified mixing ratio up to the full level.
(See "Changing Radiator Coolant " in every 2 years
maintenance.)

A Do not fill the reserve tank over the "FULL" marking.
A Do not fill with dirty or salty water.

BChecking Fuel Level

To avoid personal injury:
A Stop the engine and remove the key before

fuelling.

A Do not smoke while fuelling.

A By temperatures over -5 (23 ), use No.2-D diesel

fuel, when temperatures are under -5 (23 ), use
No.1-D diesel fuel.

A Make sure that the fuel tank is not run empty. Air will

enter the fuel system, and must be purged before
restarting.

A To prevent condensation (water) accumulations in the

fuel tank, fill the fuel into the tank before parking
overnight.

A Always fill up the fuel after a day's work.
A See "PURGING OF THE FUEL SYSTEM" in "OTHER

ADJUSTMENTS AND REPLACEMENTS".

1. Check the fuel level by the fuel level indicator.

2. Open the tank cap with the starter key, and add fuel.

(1) Reserve tank (A) "FULL"

(B) "LOW"

(1) Fuel level indicator

MAINTENANCE46

A See "Opening and Closing of the Fuel Tank Cap" and

"LCD Display for Normal Operation."

BChecking Engine Oil Level

To avoid personal injury:
A Stop the engine and remove the key before

checking the oil level.

Insert the engine oil dipstick fully into the respective port
opening, remove again and check the oil level; if
necessary fill with oil. The machine must be on level
ground when checking the oil level.

A Use engine oil with the correct viscosity. (according

the outside temperature.)

A After stopping the engine and removing the key, wait

five minutes and then check oil level. The excavator
must be on level ground.

BChecking Hydraulic Oil Level

To avoid personal injury:
A Stop the engine and remove the key before

checking the oil level.

A Before filling oil, wipe away all sand and dust from

around the oil port. Make sure to use an identical type
of hydraulic fluid.

A The excavator has been filled with hydraulic fluid

before delivery. See "RECOMMENDED OILS".
(Do not mix different oils.)

1. Park the excavator on a firm, flat and level surface.
Lower the attachments and dozer blade to the ground
and stop the engine.

2. Check the oil level as to whether it lies on the center of
the gauge at normal temperature (10 to 30 (50 to
80 )).

3. Enough oil is present if the oil level lies near the center
of the gauge.

4. Should the oil level be too low, fill oil through the oil
port before starting the engine. This step is important
for the protection of the hydraulic system.

(1) Fuel tank cap

(1) Engine oil dipstick
(2) Filling port

(A) Oil level is acceptable
within this range.

(1) Tank cap (2) Gauge

47MAINTENANCE

BLubrication Points

To avoid personal injury:
A First lower all attachments to the ground then

stop the engine and remove the key.

A While greasing, take caution not to step on the

bucket teeth.

A When doing excavation work in water,

generously grease the following points. After
ending work, grease again.

Grease the marked grease nipples shown by arrows in the
illustration below.

1. Boom bottom linkage............................. 1 place

2. Arm bottom linkage................................ 1 place

3. Bucket link pin........................................ 4 places

4. Boom cylinder boss............................... 2 places

5. Arm cylinder boss.................................. 2 places

6. Bucket cylinder boss.............................. 1 place

7. Fixing pin between arm and bucket........ 1 place

8. Boom swing fulcrum.............................. 2 places

9. Swing cylinder boss............................... 1 place

10. Swing cylinder pin.................................. 1 place

11. Dozer cylinder boss............................... 2 places

12. Dozer linkage pin................................... 2 places

MAINTENANCE48

BChecking Radiator and Oil Cooler

To avoid personal injury:
A Always stop the engine and remove the key

before checking the radiator.

A Wear eye protection when cleaning with

compressed air.

1. Check if the fins and ribs are clogged.
If so clean with compressed air or steam.

2. Check the rubber hoses for damage and replace if
cracked or old. Check if the hose clamps are tight
enough.

A Radiator and oil cooler fins and ribs must be clean in

order not to overheat the engine and allow free flow of
air through the cooling elements.

BChecking Washer Liquid(only for CAB

type)

If the windows washer is switched on with the washer
liquid tank empty, the motor may be damaged. Always
keep the tank filled.

BChecking and Cleaning Engine and

Electrical Wiring

To avoid personal injury:
A Always stop the engine and remove the key

before cleaning the wiring, cables and engine.

Before starting, check whether flammable substances
have gathered on the battery, the cables and wiring, the
muffler or on the engine. Remove thoroughly.
Check the electrical circuitry for disconnections, shorts or
loose terminals.

BWashing Whole Machine

A Do not wash the excavator with the engine running.

Water could enter the air filter and damage the engine.
Make sure that the air filter is kept dry.

A Remove the mud before washing the machine.

(1) Radiator and oil cooler

(1) Washer liquid tank

49REGULAR CHECKS AND MAINTENANCE WORK

REGULAR CHECKS AND MAINTENANCE WORK

EVERY 50 SERVICE HOURS

BDraining Fuel Tank

To avoid personal injury:
A Before draining the fuel tank, be sure to stop

the engine and remove the key.

A Do not smoke during inspection.

1. Remove the drain plug on the underside of the body
and drain water.

2. Re-tighten the drain plug.

BDraining Water Separator

1. Open the hood.

2. When the separated water enters the cup, the red float
moves upwards.
When the float reaches the line, close the cock so that
no fuel can run out. Now loosen the ring nut, and
remove the cup and empty completely.

3. Finally, do not forget to open the cock and replace the
left side cover.

BBattery

To avoid the possibility of a battery explosion:
For refillable type battery, follow the instructions
below.
A Do not use or charge the refillable type battery

if the fluid level is below the LOWER (lower limit
level) mark. Otherwise, the battery component
parts may prematurely deteriorate, which may
shorten the battery's service life or cause an
explosion. Check the fluid level regularly and
add distilled water as required so that the fluid
level is between the UPPER and LOWER levels.

To avoid personal injury:
A Never remove the vent caps while the engine is

running.

A Keep electrolyte away from eyes, hands and

clothes. If you are spattered with it, wash it
away completely with water immediately and
get medical attention.

A Wear eye protection and rubber gloves when

working around the battery.

A Before inspection or dismounting the battery,

be sure to turn off the engine and turn the
starter switch to the "OFF" position.

A When removing the battery, always disconnect

the negative ground cable first. When installing
a battery, always connect the ground cable
last. This prevents a possible explosion caused
by sparks.

(1) Drain plug

(1) Ring nut
(2) Cup
(3) Cock

(4) Float
(5) Line

REGULAR CHECKS AND MAINTENANCE WORK50

A Always wear eye protection when working with

the battery.

1. Remove the mat and cover of left side step, check the
battery fluid level and add distilled water if necessary.

2. If battery fluid be spilt, fill with sulfuric acid solution of
the same concentration.

3. Clean the battery caps (ventilation holes) also.

A When filling battery fluid or distilled water,clean

trash,dust,etc off the top of battery before opening
the battery cap.

BBattery Charging

To avoid personal injury:
A When the battery is being activated, hydrogen

and oxygen gases in the battery are extremely
explosive. Keep open sparks and flames away
from the battery at all times, especially when
charging the battery.

A When charging battery, make sure battery vent

plugs are securely.

A When disconnecting the cable from the battery,

start with the negative terminal first.
When connecting the cable to the battery, start

with the positive terminal first.

A Do not check battery charge by placing a metal

object across the terminals.
Use a voltmeter or hydrometer.

1. Make sure each electrolyte level is to the bottom of
vent wells. If necessary, add distilled water in a well­ventilated area.

2. The water in the electrolyte evaporates during
recharging. Liquid shortage damages the battery.
Excess liquid spillage damages the excavator.

3. To slow charge the battery, connect the battery
positive terminal to the charge positive terminal and
the negative to the negative, then recharge in the
standard fashion.

4. A boost charge is only for emergencies. It will partially
charge the battery at a high rate and in a short time.
When using a boost-charged battery, it is necessary to

recharge the battery as early as possible.
Failure to do this will shorten the battery's service life.

5. When the specific gravity of electrolyte falls between

1.27 and 1.29 charge has completed.

6. When exchanging an old battery for a new one, use a
battery of equal specification.

(1) Battery (2) Indicator

(A) Battery fluid level
(B) "Too low"

(C) "Correct"
(D) "Too high"

51REGULAR CHECKS AND MAINTENANCE WORK

BGreasing Swing Bearing Teeth

1. Pump grease with grease gun through the grease
nipple (at the right end side).

2. Grease at each 90 (1.58 rad.) position of the swing
frame.

3. Fill with approx. 50g of grease (approx. 20 to 30
pumps with the grease gun at each position).

EVERY 200 SERVICE HOURS

Do all 50-hour servicing at the same time.

BChecking Fan Belt Tension

C Check and adjustment of the fan belt tension

To avoid personal injury:

A First stop the engine and remove the key.
A After servicing, make sure to replace the belt

cover in its original position.

1. Press the fan belt down in the middle, with a force of
approx. 7 kg. The belt tension is correct if it deflects
about 8 mm. If otherwise, loosen bolt (1) shift the
alternator (2) in the direction shown by the arrow.

2. Replace the fan belt if worn out, cracked or torn.

A If the engine is run with a loose fan belt, the belt could

slip and cause overheating of the engine or insufficient
battery charging. Check fan belt tension regularly.

A Should the fan belt break or jump off, the indicator light

for battery charge will light up. Stop the engine and
remove the key immediately.

BChecking Radiator Hoses and Clamps

To avoid personal injury:
A Wait long enough for the radiator coolant to

cool down.

Check the water hoses for proper connection. This check
should be carried out every 200 hours or every 6 months,
whichever comes first.

1. Should the hose clamps become loose or water leaks,
tighten the hose clamps properly.

2. Should the radiator hoses become swollen, aged or
cracked, they must be replaced and the hose clamps
tightened again properly.

(1) Grease nipple

(1) Bolt
(2) Alternator

REGULAR CHECKS AND MAINTENANCE WORK52

BInspection and Cleaning Air Filter Element

Open the engine cover and remove the dust cover. Take
out only outer element, clean the element, case interior
and reassemble. During reassembly, take care to install
the dust cover with facing the TOP mark upwards. Do not
remove the inner element (safety element).

A Should the machine be used in extreme dusty areas,

the air filter element must be inspected and cleaned
more frequently than in the specified maintenance
periods.

A The air filter has a dry element, keep free from oil.
A Do not run the engine without the air filter.

(1) Radiator hoses (2) Hose clamps

(1) Radiator hoses (2) Hose clamps

(1) Outer element
(2) Inner element (safety element)
(3) Case
(4) Dust cover
(5) Clamps

53REGULAR CHECKS AND MAINTENANCE WORK

BAir Filter Maintenance

To avoid personal injury:
A Wear eye protection.

The quickest and safest method of maintenance is the
exchange of the paper cartridge. Furthermore there are
different methods of cleaning the cartridge.

C Cleaning with compressed air

Pressure of compressed air must be under 205 kPa (2.1
kgf/ ), and the cartridge should be blown clean from the
inside to the outside until the dust deposits are noticeably
reduced.

A If the air suction is still inadequate, or the color of the

exhaust gases is abnormal even after the cleaning, the
air filter cartridge must be replaced.

BGreasing Swing Bearing

1. Fill with grease through the respective grease nipple.

2. Grease at each 90 (1.58 rad.) position of the swing
frame.

(1) Grease nipple

REGULAR CHECKS AND MAINTENANCE WORK54

BChecking Fuel Line and Intake Air Line

1. Check to see that all lines and hose clamps are
tightened and not damaged.

2. If hoses and clamps are found worn or damaged,
replace or repair them at once.

EVERY 250 SERVICE HOURS

Do all 50 hour servicing at the same time.

BChanging Engine Oil(First Engine Oil

Change after 50 Service Hours)

To avoid personal injury:
A First stop the engine then remove the key and

wait long enough for the oil to cool down.

1. Remove the drain plug on the underside of the engine
and drain all oil.

2. Re-tighten the drain plug.

3. Fill through the filling port up the specified level.

4. Let the engine idle for approx. 5 min. Check the engine
oil level. To check the engine oil level, insert the
engine oil dipstick completely into the respective port
opening and pull out again. If the oil level lies between
both markings, no oil must be added.

(1) Fuel lines
(2) Clamp bands

(1) Hoses
(2) Hose clamps

(1) Drain plug

(1) Oil filling port

55REGULAR CHECKS AND MAINTENANCE WORK

A Regardless of the service hours, an engine oil change

is due every six months.

EVERY 500 SERVICE HOURS

Do all 50 and 250 hour servicing at the same time.

BReplacing Engine Oil Filter(Replace the

engine oil filter every 500 hours,or every 1
year in the case that service hour is less
than 500 hours)

1. Replace the oil filter cartridge at the same time as
doing the engine oil change.

2. Remove the cartridge with the supplied filter wrench.

3. Oil the O-ring of the new oil filter cartridge lightly. Then
tighten the oil filter cartridge by hand.

4. Fill engine oil to the specified level.

5. Let the engine run for approx. 5 min. and make sure
that the engine oil indicator lamp does not light up.
Then stop the engine and remove the key.

6. The engine oil level is reduced by the amount of the
filter capacity after the engine is started. It is necessary
to add oil.

A Always check the oil level after having exchanged the

filter.

BDrive unit Oil Change(First Oil Change at

100 hours)

To avoid personal injury:
A Lower to the ground, stop the engine and

remove the key before undertaking the oil
change.

1. Rotate the track so that the drain plug of the drive unit
is in the bottom position.

2. Remove the drain plug to let the oil run out. Screw in
and tighten the drain plug again and fill with gear oil
through the oil check port.

3. Fill oil until it overflows out of the oil check port.

Oil change

- first oil change after 100 hrs

- then every 500 hrs

- or at least once a year

4. Use prescribed gear oil SAE 90.

(1) Oil filter

Engine oil volumes

(with engine oil filter)

5.9 L

(1) Oil check port
(2) Drain plug
(3) Oil filling port

Gear oil volume approx. 0.6 L

REGULAR CHECKS AND MAINTENANCE WORK56

BReplacing Fuel Filter Cartridge

To avoid personal injury:
A Keep fire away.

1. Remove the filter with the supplied filter wrench.

2. Add fuel to a new filter before installing.

3. Apply a light film of fuel to the seal of the new filter and
turn in tightly by hand.

4. Open the cock of the fuel filter again.

A After exchange of the filter, the fuel system must be

purged of air.

BReplacing Hydraulic Return Filter

Element(first replacement after 250
service hours)

To avoid personal injury:
A Remove the oil filter only after the oil in the

hydraulic tank has cooled down.

1. Remove the cover of the hydraulic tank.

2. Pull out the filter support by the top plate from the
hydraulic tank.

3. Remove the return filter from the filter support with a
fork wrench and exchange the filter.

A Always check the oil level when replacing the filter.

(1) Fuel filter cartridge

(1) Set bolt
(2) Filter support

(3) Return filter
(4) Cover

57REGULAR CHECKS AND MAINTENANCE WORK

EVERY 1000 SERVICE HOURS

Do all 50, 100, 200, 250 and 500 hour servicing at the
same time.

BHydraulic Oil Check for Machines with

Hydraulic Breakers

The hydraulic oil change after 1000 operating hours in the
operator's manual is based on the type of work done.
Following inspection measures are valid when hydraulic
breakers are used:

1. Changing and filling up of hydraulic oil
(1) The hydraulic oil must be changed more often

when breakers are used because the machine is
subject to harder conditions than normal
excavating work.

(2) Use only the recommended oils mentioned in the

operator's manual when changing or filling with
oil.

(3) When filling up oil, never mix oils of different

makes.

2. Changing the return filter and oil
(1) The filter must be changed more often because of

contamination resulting from the frequent

assembly and disassembly of the hoses.
(2) Use the correct replacement filter.
(3) Oil change according to operating hours.

BHydraulic Oil Change(Including Replacing

Suction Filter and Breather Filter Element
in Hydraulic Tank)

To avoid personal injury:
A Wait long enough for the hydraulic fluid to cool

down. Then begin with the change of the
hydraulic fluid.

1. Park the excavator on a firm, flat and level surface.
Lower the attachments and dozer blade to the ground
and stop the engine.

2. Remove the drain plug on the underside of the
hydraulic tank and drain the oil.

3. Remove the cover of the hydraulic tank.

4. With a fork wrench or similar, remove and replace the
filter with new one.

5. Retighten the drain plug, and remove iron powder
adhering to the magnet.

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(1) Set bolt
(2) Filter support
(3) Return filter
(4) Cover

(5) Suction filter
(6) Drain plug
(7) Bolt
(8) Breather filter

REGULAR CHECKS AND MAINTENANCE WORK58

6. Fill oil through the oil filling opening on the top side of
the tank.

7. Let the engine run for approx. 5 min. and check the oil
level again.

A Should dirt deposits be in the hydraulic tank, remove

with the help of a clean cloth and light oil.

BReplacing Hydraulic Pilot Filter Element

To avoid personal injury:
A Before replacing the element, wait long enough

for the hydraulic fluid to cool down.

1. Remove the arch cover.

2. Remove the hydraulic oil tank cover.

3. Remove the pilot filter case from the head cover.

4. Wrench and pull out the element downward.

5. Replace the O-ring with a new one.

6. Apply a light coating of clean hydraulic oil to the O-ring
and fit it to the case firmly. Be careful not to scratch the
O-ring.

7. Install the case to the head cover firmly.

8. Let the engine run for approx. 3 minutes.

9. Check the oil level of hydraulic oil tank.

EVERY 1000 SERVICE HOURS OR ONCE A
YEAR

BReplacing Air Filter Element

Open the engine cover and remove the dust cover.
Take out outer element and inner element (safety
element).
Replace inner and outer element.
Installing the dust cover, be sure to its TOP mark (arrow)
faces upwards.

A Shorten the replacement period if using in a place

exposed to lots of dust or sandy areas.

EVERY 1500 SERVICE HOURS

BChecking Fuel Injection Nozzle(Injection

Pressure)

Consult your local KUBOTA Dealer for this service.

EVERY 2000 SERVICE HOURS

Do all 50, 200, 250, 500 and 1000 hour servicing at the
same time.

BChanging Front Idler and Track Roller Oil

A Contact your KUBOTA dealer for details.

BChecking Alternator and Starter Motor

A Contact your KUBOTA dealer for details.

Hydraulic oil volumes 55 L

(1) Head cover
(2) Element
(3) O-ring
(4) Case

(1) Outer element
(2) Inner element (Safety element)
(3) Case
(4) Dust cover
(5) Clamps

59REGULAR CHECKS AND MAINTENANCE WORK

EVERY 3000 SERVICE HOURS

BChecking Injection Pump

Consult your local KUBOTA Dealer for this service.

ANNUAL SERVICE

BElectrical Wiring and Fuses

Check the terminals periodically for proper connections.
Loose wiring or damaged cables can cause improper
functioning or short circuiting of the electrical system.
Check wiring and replace damaged components
immediately. If a fuse blows out soon after having been
replaced, contact your nearest KUBOTA dealer. Do not
use a fuse other than specified.

BIENNIAL SERVICING

To avoid personal injury:
A Do not loosen the radiator cap before the

radiator has cooled down sufficiently. Then
only loosen the cap and allow enough time for
the pressure in the system to be released. Now
remove the cap completely.

BReplacing of Radiator Hoses

Replace radiator hoses and hose clamps every two years.
If the hoses are swollen, hard or cracked, they must be
replaced earlier.

BChanging Radiator Coolant

To avoid personal injury:
A When using anti-freeze, put on some protection

such as rubber gloves (Anti-freeze contains
poison.).

A If anti-freeze has been swallowed, seek medical

attention at once.

A When anti-freeze comes in contact with the

skin or clothing, wash it off immediately.

A Do not mix different types of Anti-freeze. The

mixture can produce chemical reaction
causing harmful substances.

A Anti-freeze is extremely flammable and

explosive under certain conditions. Keep fire
and children away from anti-freeze.

A When draining fluids from the engine, place

some container underneath the engine body.

A Do not pour waste onto the grounds, down a

drain, or into any water source.

A Also, observe the relevant environmental

protection regulations when disposing of anti­freeze.

A Anti-freeze if swallowed is poison to people,

animals and birds.

Stop the engine then remove the key and wait until it has
cooled down completely.

1. Open the drain plug on the bottom of the radiator and
drain coolant completely, Should a reserve tank be
equipped, disconnect the line from the tank floor and
then open the drain cock.

2. To clean, rinse the radiator with water.

3. Close the drain plug and fill the radiator and the
reserve tank with coolant fluid. Let the engine idle for
about 5 min., stop the engine and remove the key then
check the coolant level.

(1) Radiator hoses
(2) Hose clamps

(1) Radiator hoses
(2) Hose clamps

REGULAR CHECKS AND MAINTENANCE WORK60

4. The machine has been shipped filled with 50% anti­freeze solution.

A Do not operate the engine without coolant.

A To fill the radiator system and the reserve tank, use

fresh water and anti-freeze fluid.

A When the anti-freeze is mixed with water, the anti-

freeze mixing ratio must be less than 50%

A Tighten the radiator cap properly. If the cap is loosely

or not properly fitted, overheating of the engine can
result due to coolant fluid loss.

BReplacing Fuel Hose

Replace the hoses and clamps.
(See "Checking Fuel and Intake Air Line" every 200 hours
maintenance.)

BReplacing Intake Air line

Replace the hoses and clamps, if necessary.
(See "Checking Fuel and Intake Air Line" every 200 hours
maintenance.)

(1) Drain plug

(1) Radiator cap

(2) Reserve tank (A) Full

(B) Low

Radiator approx. 4.0 L

Reserve tank approx. 1.6 L

(1) Fuel lines
(2) Clamp bands

(1) Hoses
(2) Hose clamps

61OTHER ADJUSTMENTS AND REPLACEMENTS

OTHER ADJUSTMENTS AND REPLACEMENTS

PURGING FUEL SYSTEM

1. Fill up the excavator with fuel.

2. Turn the starter key to the position "RUN".

3. The air in the fuel system will automatically be purged
within one minute.

A If the purging was insufficient, the engine dies right

after starting. In this case repeat steps (2) to (3) again.

ADJUSTMENT OF TRACKS

BRubber Tracks

Tension the tracks as specified:

1. Loosen the bolt (1) and remove the cover (2).

2. Apply grease (4) to the grease nipple (3).

3. Tension the track in the lifted position, so that the
distance "A" (clearance between the center track roller
and the track surface of the track) is 10 to 15 mm (see
illustration) In this case, the track seam is positioned
on the top center between the idler and the sprocket.

To avoid serious injury or death:
A Do not work under the machine in this

condition.

A For your safety do not rely on hydraulically

supported devices, they may leak down and
suddenly drop or be accidentally lowered.

(1) Starter switch (A) "STOP"

(B) "RUN"
(C) "START"

(1) Bolt
(2) Cover

(3) Grease nipple
(4) Grease gun (Option)

(1) Seam (Mark " ")

(A) 10 to 15 mm

OTHER ADJUSTMENTS AND REPLACEMENTS62

A Track seam

The ends of the rubber track are joined with a seam.
When adjusting the tracks, the seam must be
positioned on the top midway between the idler and
the sprocket. By machines equipped with an upper
roller, the seam mark should be positioned over the
upper roller.
If the seam is positioned incorrectly, the tracks will be
tensed to loosely, and a further readjustment will be
necessary.

A Rotate the track after adjustment one to two times to

check the tension. To loosen the rubber tracks, follow
the same method as for steel tracks.

A Additionally following points are to be observed when

adjusting rubber tracks.
(1) If the track slackens more than 25 mm, readjust

them.

(2) Check track tension 30 hours after initial use and

readjust if necessary. Check and adjust thereafter
every 50 service hours.

BSpecial Information when Using Rubber

Tracks

1. When turning, make a slow swing turn. Avoid spin
turns to reduce lug wear and entry of dirt.

2. The relief valve may be activated if too much dirt and
sand clog the tracks. In this case move the machine for
a short distance straight backwards to let the earth and
sand fall off, then a turn can be made.

3. Avoid using rubber track on riverbeds, stony
underground, ferro-concrete and on iron plates. The
rubber can damage as well as increase wear on the
tracks.

BSteel Tracks

C Track shoe plate tension

1. Loosen bolt (1) and remove the cover (2).

2. Apply grease (4) to the grease nipple (3).

3. To check the track tension, the track must be lifted
from the ground as shown. The track tension is correct
if the clearance between the outer end of the track
roller and the track interior surface corresponds to the
dimension specified in the table below.

To avoid serious injury or death:
A Do not work under the machine in this

condition.

A For your safety do not rely on hydraulically

supported devices, they may leak down and
suddenly drop or be accidentally lowered.

(1) Bolt
(2) Cover

(3) Grease nipple
(4) Grease gun (Option)

(1) Drive sprocket
(2) Idler

(A) 75 to 80 mm

63OTHER ADJUSTMENTS AND REPLACEMENTS

C To loosen the tracks, follow following procedure:

To avoid personal injury:
A Do not loosen the grease nipple completely or

too quickly. Otherwise grease under high
pressure in the tension cylinder could squirt
out.

A Make sure that no obstacles, such as stones

are caught in the track. Remove such obstacles
before adjusting the track tension.

1. Loosen the bolt of the cover and remove the cover.

2. Using a socket wrench, loosen the grease nipple a few
turns.

3. When grease oozes out from the thread, rotate the
track and loosen the track in the lifted position (see
illustration).

After adjustment is completed:

Using the socket wrench, tighten the grease nipple.
Tightening torque must be between 1000 to 1100 kgf-cm.

A If the tracks are too tight, wear is increased.
A If the tracks are too loose, the track pads may collide

with the sprocket, wear is increased.
The track may dislocate or come off.

A Clean the track after every use.
A Should the track tension be high due to sticking mud,

lift the track with the help of the boom, arm and bucket,
idle the engine and remove mud from the track,
especially from the openings of the link plate carefully.

CHANGING THE BUCKET

To avoid personal injury:
A When the coupling pins are removed or

installed, chips may come off. Always use
gloves, goggles and a helmet.

A When the change of the equipment must be

performed with the engine running, always
work as a 2-person team.
One person sits in the operator's seat and the
other works on the machine.

A Do not use your fingers to center the holes,

since they may be injured or even cut in case of
sudden or uncontrolled movements.

A Read the manual of the attachment to do a

correct operation safely when other
attachments are installed instead of Kubota
specified bucket.

FUSES

To avoid personal injury:
A When changing fuse, stop the engine and turn

the key in position "STOP".

BReplacing Fuses

1. Remove the cover of the fuse box.

2. Replace the burnt out fuse with a fuse having the same
capacity.

BFuse Capacities and Circuits

5A Room Light 10A Heater Fan

20A Work Light 15A AI Motor

5A Meter Sub

10A Alternator

5A Lock Lever

10A Horn

15A Cigarette Lighter 10A Meter Main

15A Auxiliary 5A Travel Hi-Low

15A Wiper / Washer 5A Relay Source

OTHER ADJUSTMENTS AND REPLACEMENTS64

BAuxiliary Electric

Max power is less than 110 W including the equipped light
55 W.

BSlow Blow Fuse

Slow blow fuse is provided to protect the electrical circuits.
If the fusible link is blown, check the electrical circuits for
trouble and then replace with a new compatible slow blow
fuse.

(1) Fuse box
(2) Auxiliary electric A

(1) Fuse box
(2) Auxiliary electric A

(1) Slow blow fuse (50 A)

(1) Slow blow fuse (60 A)

65TROUBLESHOOTING

TROUBLESHOOTING

If the mini-excavator does not show the desired performance, or when trouble arises, refer to the table below and undertake
appropriate measures.

Trouble Cause Countermeasure

Engine

Starting
difficulties

Lock levers in "UNLOCK"
position

* Bring lock lever into "LOCK" position.

Fuel is too viscous.

* Check fuel tank and filter.
* Remove impurities and water.
* If necessary, replace filter.

Air or water in the fuel
system

* Remove water from the fuel tank.
* Check fuel pipe joint bolts and nuts for looseness.
* Purging of the fuel system (for fuel filter and injection pump,
see "PURGING FUEL SYSTEM" in the chapter.
"OTHER ADJUSTMENTS AND REPLACEMENTS".)

Oil viscosity is so high that
the engine runs sluggishly
in winter.

* Pour hot water over the radiator.

Battery is almost dead;
insufficient compression.

* Recharge battery.

Insufficient
engine power

Low fuel level * Check fuel and add if necessary.

Clogged air cleaner * Clean the air filter element.

Engine suddenly
stops.

Low fuel level

* Check fuel and add if necessary.
* Purge the fuel system.

Abnormal
exhaust gas
color

Poor fuel * Use high quality fuel.

Too much engine oil * Drain engine oil to prescribed oil level.

Water
temperature
in red zone
(Overheating)

Defective seal of the water
pump

* Replace.

Worn or torn fan belt * Adjust or replace.

Thermostat is defect. * Replace.

Coolant level too low * Fill to prescribed level.

Radiator grill or fins are
clogged.

* Clean.

Coolant is contaminated
with rust from the cylinder
head or crank case.

* Replace coolant fluid and add anti-rust.

Defective radiator cap
(Evaporation)

* Replace.

Corroded coolant pipes * Clean.

Continuous operation
under full load

* Reduce load.

66 TROUBLESHOOTING

Engine

Water
temperature
in red zone
(Overheating)

Cylinder head gasket is
damaged (Coolant loss).

* Replace.

Engine oil level too low * Fill to prescribed level.

Maladjustment of fuel
injection

* Readjust ignition timing.

Use of poor fuel * Use prescribed fuel.

Hydraulic
System

Boom, arm,
bucket, drive,
swing and dozer
power is too low.

Hydraulic oil level too low * Add oil.

Leakages of hoses and /
or joints

* Replace hose or joint.

Swing motor and
front attachment
does not work.

Lock lever in "LOCK"
position

* Bring lock lever into "UNLOCK" position.

Drive
System

Deviation of
drive direction

Blocked through stones * Remove.

Track too loose or too tight * Adjust accordingly.

Drive lever does
not move.

Lock lever in "LOCK"
position

* Bring lock lever into "UNLOCK" position.

Trouble Cause Countermeasure

67TROUBLESHOOTING

KUBOTA I.C.S. NAVIGATION LIST OF MESSAGES

If an error occurs with the machine, one of the following messages appears in the LCD display.
In case of a trouble, immediately contact your local dealer for inspection and repair.

Message

Warning

lamp Color

Problem or failure

(what happened)

Machine behavior

(provisional measure)

Correction

yellow Fuel running out. - Add fuel.

red

Engine oil circuit error
(clogged) or engine oil
shortage.

Immediately stop the
engine.

The engine may
be seized, failing
to restart the
engine.
Immediately
contact your local
dealer for repair.

red

Charging line in trouble.
Charging failure.

Check the fan belt.
(When the belt is in
good condition, keep
running until the
battery becomes
dead.)

Immediately
contact your local
dealer for repair.

red

24V line engine startup
alternator defective.

[Do not start the
engine on 24V line.
Get it restarted to see
if there is the
message again.]

If the message
does not
reappear, no
repair is needed.
If the message
stays on, contact
your local dealer
for repair.

yellow

The engine has been
started with the lock
lever down.

The engine fails to
start.

Pull up the lock
lever and start the
engine.

yellow

The hour meter has
reached the specified
count-up. Carry out the
maintenance job.

-

Carry out the
specified
maintenance job.

No message
(warning lamp flashing)

red

Sensor power line short
circuited.

The work light lights
up.

Immediately
contact your local
dealer for repair.

68 TROUBLESHOOTING

C Service hour meter

When the hour meter has counted up to the hours circled in the maintenance list below, the message appears. The
message shows up as follows.

The message appears. The message shows up as follows.

(The message reappears on the hour meter designated next.)

A The maintenance message disappears automatically in about 10 seconds.
A When the key is turned from OFF to RUN, the maintenance message reappears and disappears again automatically in

about 10 seconds.

A When the key is turned from OFF to RUN repeatedly 10 times, the message disappears.

C In case the service hour meter replaced due to any trouble with it, the meter is set to "0". Contact your KUBOTA dealer

for details.

No. Check points

Measures

Hour meter indicator

Interval

50 100 250 300 500 550 600 750 800 1000

1 Engine oil

change

every 250 hrs

or every 1 year

2 Hydraulic oil every 1000 hrs

3

Air filter

element

Outer

element

replace

every 1000 hrs

Inner

element

every 1000 hrs

4 Drive unit oil change every 500 hrs

5 Engine oil filter

replace

every 500 hrs

or every 1 year

6

Hydraulic return filter

element

every 500 hrs

7

Hydraulic breather

filter element

every 1000 hrs

8

Hydraulic suction filter

element

every 1000 hrs

First operation

69OPERATION UNDER COLD WEATHER CONDITIONS

OPERATION UNDER COLD WEATHER CONDITIONS

PREPARATION FOR OPERATION IN COLD
WEATHER

1. Replace engine oil and hydraulic oil with those of
viscosities suitable for cold weather.

2. In cold weather, battery power drops, and the battery
fluid may freeze if the battery is not sufficiently
charged. To prevent the battery fluid from freezing, be
sure to keep the battery charged at least 75% or more
of its capacity after operation. To ease next starting, it
is recommended to keep the battery stored in closed
or heated rooms. If the battery fluid level is too low, do
not add after operation, but add with the engine
running before the next operation.

3. Add anti-freeze to coolant in the radiator and reserve
tank, if the ambient temperature is expected to drop
below 0 (32 ). Mixing ratio of water and anti-freeze
depends on the expected ambient temperature.

A Mixing ratio between water and anti-freeze

A Use permanent anti-freeze or long-life coolant.
A Drain the coolant completely and clean the inside of

the radiator, then fill with the water and anti-freeze
mixture.

A The anti-freeze acts as an anti-corrosive, it is not

necessary to add an additive to the water and anti­freeze mixture.

A See "Coolant check" under "DAILY CHECKS" in

"MAINTENANCE" for radiator fill volumes.

PROCEDURE AFTER DONE WORK

Clean the excavator thoroughly after work and wipe dry.
Otherwise mud and earth on the tracks could freeze if the
temperature drops below the 0 (32 ) mark. Operation
of the excavator is then not possible. Store the excavator
in a dry place; if not possible, store on wooden planks or
on mats. If the excavator is kept on damp or muddy
ground, the tracks could freeze overnight. Operation of
the excavator is then not possible. Furthermore the
reduction gear may be damaged.
Additionally, the piston rods of the hydraulic cylinders
must be rubbed dry. Otherwise severe damage could
occur if dirty water seeps through the seals.

Ambient
Temperature ()

-5

(+23)

-10

(+14)

-15

(+5)

-20
(-4)

-25

(-13)

-30

(-22)

-35

(-31)

Antifreeze % 30303035404550

Water % 70707065605550

70 LONG STORAGE

LONG STORAGE

To avoid personal injury:

A Do not clean the excavator with the engine running.
A To avoid the danger of exhaust fume poisoning, do not operate the engine in a closed building without

proper ventilation.

A When storing, remove the key from the starter switch to avoid unauthorized persons from operating the

excavator and getting injured.

B Should the Excavator be Stored for a Longer Period of Time, Observe Following Procedures:

1. The whole excavator should be cleaned thoroughly and in all cases stored indoors. If the excavator has to be kept
outdoors, lay out wooden planks on even ground, place the excavator on the planks and cover completely.

2. Do an oil change and grease the excavator.

3. Heavily grease the visible section of the cylinder rods.

4. Remove the battery and store indoors.

5. If it is expected that the temperature will sink below the 0 (32 ) mark, add anti-freeze or drain coolant completely.

A Wash the excavator after stopping the engine.

If you wash the excavator while running the engine, splashing water gets into the air cleaner through its intake and
cause engine damage.
Carefully, wash and do not splash water over the air cleaner while the engine is running.

B Observe Following Procedures when the Machine is to be Operated after Long Storage.

1. Wipe off the grease from the hydraulic cylinder rods.

2. Turn on the engine and operate the attachments and the drive mechanisms under no load in order to circulate the
hydraulic oil.
(If the machine is stored for longer than one month, do steps 1 and 2 once every month.)

71LONG STORAGE

Periodic replacement of important component parts
To ensure safety in operation, you are strongly requested to inspect and service the machine at regular intervals. For added
safety, ask your KUBOTA dealer to replace the following important component parts.
These parts are prone to degradation in material or subject to wear and tear with time. It is difficult to judge how much they
have been affected at regular inspection. It is therefore necessary to replace them with new ones, whether wear is visible
or not after a specified time of use.
If any of them is found to be worn before the specified use, they must be repaired or replaced the same as other parts.
If any of the hose clamps are found deformed or cracked, the hose clamps must also be replaced.
For the hydraulic hoses other than the ones to be replaced periodically, inspect them for the following points. If found loose
or very worn, tighten and / or replace the hose.
When replacing the hydraulic hoses, change their O rings and sealing components with new ones.
For replacement of the important parts, contact your KUBOTA dealer.

A At the following periodic inspections, check the fuel hoses and hydraulic hoses as well.

List of important component parts

To prevent serious damage to the hydraulic system, use only a KUBOTA genuine hydraulic hose.

Inspection Interval Check points

Daily Checks Oil leak at fuel and hydraulic hose connections and points

Every month

Oil leak at fuel and hydraulic hose connections and points
Damages at fuel and hydraulic hose (cracks, chafing)

Every year

Oil leak at fuel and hydraulic hose connections and points
Interference, deformation, degradation, twist and other damages (cracks, chafing) of fuel and hydraulic
hoses

No. Component parts Used place Q'ty Period

1 Fuel hose

Fuel tank - Fuel filter 1

Every 2 years or
4000 hours

Fuel filter - Fuel pump 1

Fuel pump - Fuel nozzle 1

Fuel nozzle - Fuel tank 2

2 Hydraulic hose (suction)

Tank - Pipe 1

Pipe - Main pump 1

3 Hydraulic hose (delivery)

Main pump - Control valve 3

Main pump - Pilot filter 1

Pilot filter - Change valve 1

4 Hydraulic hose (Boom cylinder)

Control valve - Adapter 2

Adapter - Boom cylinder 2

5 Hydraulic hose (Arm cylinder)

Control valve - Pipe, Boom 2

Pipe, Boom - Arm cylinder 2

6 Hydraulic hose (Bucket cylinder)

Control valve - Pipe, Boom 2

Pipe, Boom - Bucket cylinder 2

7 Hydraulic hose (Swing cylinder) Control valve - Swing cylinder 2

8 Hydraulic hose (Dozer cylinder)

Control valve - Rotary joint 2

Rotary joint - Pipe 2

Pipe - Dozer cylinder 2

9 Hydraulic hose (Service port)

Control valve - Pipe, Boom 2

Pipe, Boom - Pipe, Boom 2

Pipe, Boom - Pipe, Arm 2

10 Hydraulic hose (Swivel motor) Control valve - Swivel motor 2

72 RECOMMENDED OILS

RECOMMENDED OILS

1. Before delivery the hydraulic oil used was an ISO 46 viscosity grade.

2. Use engine oil API service classification CF.

3. Use SAE 90 (API, CLA/GL5) as drive unit oil for all seasons.

Application Viscosity Shell Mobil Exxon MIL-Standard

In winter or by
low
temperatures

SAE
10W

Shell Rotella T10W
Shell Rimula 10W

Mobil Delvac 1310

XD-3 10W
XD-3 Extra 10W

SAE
20W

Shell Rotella T20W-2
Shell Rimula 20W-2

Mobil Delvac 1320

XD-3 20W-20
XD-3 Extra 20W-20

In summer or
by high ambient
temperatures

SAE30Shell Rotella T30

Shell Rimula 30

Mobil Delvac 1330

XD-3 30
XD-3 Extra 30

SAE40Shell Rotella T40

Shell Rimula 40

Mobil Delvac 1340

XD-3 40
XD-3 Extra 40

SAE

50

Shell Rimula 50 Mobil Delvac 1350

All- Season
engine oil

Multi-

purpose

Shell Rotella T15W-40

XD-3 15W-40
XD-3 Extra 15W-40

In winter or by
low
temperatures

SAE

75

Mobilube HD80W-90

MIL-L-2105C

Shell Oil S8643

SAE

80

Mobilube HD80W-90

Shell Spirax HD80W

In summer or
by high ambient
temperatures

SAE

90

Mobilube 46 MIL-L-2105

Shell Spirax HD90 Mobilube HD80W-90 MIL-L-2105C

SAE

140

Mobilube HD85W-140 MIL-L-2105C

Shell Spirax HD140 Mobilube HD80W-140 MIL-L-2105C

All-weather
gear oil

Multi-

purpose

Shell Spirax HD80W
Shell Spirax HD85W

Mobilube HD80W-90 GX80W-90 MIL-L-2105C

In winter or by
low
temperatures

ISO

32

Shell Tellus T32 Mobil DTE-Oil 13 NUTO H32

ISO

46

Shell Tellus T46 Mobil DTE-Oil 15 NUTO H46

In summer or
by high ambient
temperatures

ISO

68

Shell Tellus T68 Mobil DTE-Oil 16 NUTO H68

Grease Shell Alvania EP2 Mobilux EP2 BEACON Q2

Fuel Light oil No. 2-D (ASTM D975)

Fuel under 5 C

(+23 F)

Light oil No. 1-D (ASTM D975)

MIL-L-2104C
MIL-L-2104D

Engine oilGear oilHydraulic oil

73APPENDICES

APPENDICES

MAIN DIMENSIONS

*until the end of the track.

With rubber track.

Dimensions in parentheses: CAB type models mm

(A) (B) (C) (D) (E) (F) (G) (H) (I) (J)

KX91-3S2 410 475 1550 4940 3530 3185 2390 1310 3485 5245

U35-3S2 600 635 1700

4945

[4720]

3525

[3315]

3140 2230 850 3665 5260

(K) (L) (M) (N) (O) (P) (Q) (R) (S)

KX91-3S2 370 370 2440 1550 5135 1310 4795 1440 1900

U35-3S2 370 370 2440 1700 5145 1030* 4965 1440

2015

[2145]

74 LIFTING CAPACITY

LIFTING CAPACITY

1. The lifting capacities are based on ISO 10567 and do not exceed 75% of the static tilt load of the machine or 87% of
the hydraulic lifting capacity of the machine.

2. The strokes are as follows.
(1) The load point corresponds to the front bolt part of the arm.

(2) The machine positions are (i) over - front (Blade down), (ii) over - front (Blade up), and (iii) over - side.
(3) The operating cylinder is the boom cylinder.

3. The bucket of the excavator, the hook, the sling and other lifting accessories are taken into consideration for the loads.

Machine conditions:
No bucket, all others according to the standard regulations.

To avoid personal injury or death:

A No loads greater than those values mentioned in the lifting capacity tables are to be lifted.
A The values mentioned in the table are valid only on even, hard grounds. When lifting on soft ground, the

machine can tip over due to the load being concentrated only on one side of the machine.

A The table values are calculated at the end of the arm without the bucket. In order to find the allowable loads

for machines with bucket, the bucket weight must be subtracted from the values in the table.

75LIFTING CAPACITY

76 LIFTING CAPACITY

77LIFTING CAPACITY

78 LIFTING CAPACITY