Hyundai Mini R28-7SM Service Manual

SERVICE MANUAL

SER. NO. HY2870001~

INTRODUCTION

To insure a long life for the machine and the engine and to prevent failure and problems,
proper operation, maintenance and repairs are imperative.

This service manual includes an “outline,” “structure and operation,” “inspection and ad­justment,” “disassembly and assembly ,” “standard maintenance,” and “repair and replace­ment of parts” of the machine which are necessary to carry out the inspections and repairs
in the repair shop.

We trust that this manual will help you to effectively carry out the necessary. Repairs
should they arise, also provide a accurate description of the product, and the correct
repair procedures.

CONTENTS

1. Precautions on Maintenance

2. Outline

3. Attachment

4. Engine

5. Main Pump

6. Hydraulic Oil Filter

7. Control Valve

8. Joystick
(Pilot Valve)

9. Pilot Valve (1)
(Travel)

10. Pilot valve (2)
(Swing, PTO)

11. Pilot Valve (3)
(Dozer)

12. Slew Motor

13. Travel Motor

14. Hydraulic Cylinder

15. Swivel Joint

16. Crawler

17. Spring Case and Grease Cylinder

18. Idler

19. Sprocket

20. Track Roller

21. Carrier Roller

22. Electrical Equipment

23. Troubleshooting

1 PRECAUTIONS ON MAINTENANCE

1. Correct operation

Correct operation means to follow the correct “procedure” and “method.”
Procedure focuses on speed and accuracy of each job.
In the method, are addressed what type of facility, tools, instruments, materials, oil should
be used, how and which part should be checked, adjusted or disassembled, and what
matters to attend to.

2. Precautions on operation

1. Safety check
Check that stoppers and sleepers are correctly installed for the vehicle jack-up
operation.

2. Preparation
Prepare all of the tools and inspect and adjust the instruments.

3. For efficiency

1) Understand the state before disassembly.

What is the problem? Is disassembly absolutely necessary?

2) Before disassembly

Determine whether match marks are necessary. For the electrical system, discon­nect the cable from the battery terminal.

3) Precautions for disassembly

In stead of checking all of the disassembled parts at once, check each part
individually as it is disassembled. When removing the hydraulic unit or the hoses,
mount a dust cap on the connection.

4) Repair of disassembled parts

Keep the disassembled parts in order. Clearly distinguish the parts to be replaced
with new parts from those to be reused. Packings, seals, rings, split pins must be
replaced.

NOTE:

Electrical equipment, rubbers and V belts (which are easily affected by water and
oil) must be handled carefully in order to prevent soiling them.

5) Clean disassembled parts

Thoroughly clean the disassembled parts.

6) Assembly

Perform the assembly correctly (tightening torque, application of Three Bond,
screw lock, grease, use of seal tape, etc.). Also install the hose correctly.

Hose mark Hose mark

1-1

2 OUTLINE

CONTENTS

2-1 Location of serial No.
2-2 Name of each part
2-3 Dimensions and specification

2-3-1 H26C PTO flow
2-4 Weight list
2-5 Oil and grease supply points
2-6 List of supply oil and grease
2-7 When to repair
2-8 Hydraulic circuit diagram

2-1 Location of Serial Number

Model Name.
Serial No.

2-1

2-2 Name of each part

15

14

6

16

13

12

10 9

11

3

5

1. Meter unit

2. Starter switch

8

3. Horn switch

4. Fuse box

5. Right operation lever

6. Left operation lever

7. Accelerator lever

1

8. Dozer lever

9. Right travel lever

10. Left travel lever

7

11. Swing pedal

12. P.T.O. pedal

13. Operation lock lever

14. Over drive switch

15. Hearter switch (for cabin)

2

16. Wiper switch (for cabin)

17. Manual boom lower lever

18. Cigarette lighter

18

4

17

1. Water temperature meter

4

5

6

2. Fuel gauge

3. Hour meter

4. Charge lamp

7

H

1



R

E

T

A

P

W

M

E

T

C

F

L

E

U

F

E

0

0 0



0

R

U

0

O

R

H

0

E

T

E

M

9

5. Engine oil pressure lamp

6. Glow lamp

7. Air filter lamp

8. Head light switch

9. Heater change lever
(cold↔warm

)

2

3

8

2-2

2-3 Dimensions and Specifications

2-3

Machine
weight

Standard
bucket

Engine

Working
range

Dimension

Performance

Under­carriage

Hydraulic

Capacity

Noise

Description Unit Robex28-7

Rubber shoe 2750

Canopy

Cabin

Steel shoe 2760
Rubber shoe 2660

Kg

Steel shoe 2670

Capacity m

3

0.07
Width mm 450
Maker, model MITSUBISHI S3L2
Rated power ps(kW)/min

-1

24.1(17.7)/2100
Displacement cc 1318
Arm length 1165(std.) 1465(long)
Max.digging depth 2610 2900
Max.vertical digging depth 1870 2140
Max.digging height 4380 4575
Max.dumping height 3020 3220
Max.digging reach mm 4590 4830

Min.swing radius

Front 1890 1950

Swing 1530 1580
Rear end radius 1350
Boom swing angle deg Left80/Right50
Overall length 4420
Overall width

mm

1470
Overall height 2385
Dozer(width × height) 1470×300
Travel speed km/hr 2.8/4.0
Swing speed min

-1

10.3

Gradeability deg(%) 30(58)
Max.digging force

Bucket 25.6(2610)
Arm kN(kgf) 15.6(1595)

Max. drawbar pull 24.1(2460)
Ground

pressure

Canopy&rubber shoe
Cabin&rubber shoe 29.5(0.30)

Tumbler distance × track gauge

kpa(kgf/cm2)

mm

30.4(0.31)

1360×1150
Track shoe width 300
Type of travelling motor Piston shoe-in type
Crawler tension system Grease cylinder
Type of hydraulic pump Piston×2, Gear×1
Pump oil flow

/min

2×33.6+22.1
Auxiliary circuit oil flow 55.7
Relief valve setting pressure MPa(kgf/cm2) 20.6/17.2(210/175)
Hydraulic oil tank 50.5
Engine oil 4.5
Fuel tank 42
Cooling water 5.5
Noise level(LwA/LpA) dB 94/78

2-4

2-3-1 Robex 28-7 PTO Flow

2-5

2-4 Weight list

Part name Robex 28-7 Part name Robex 28-7
Boom 98 Swing cylinder 22
Arm 55 Dozer cylinder 18
Bucket 51 Turning bearing 42
Dump link 10 Track frame 280
Bucket link 2.8×2 Dozer 113
Boom joint pin 2.6 Steel crawler 156×2
Arm joint pin 1.6 Rubber crawler 138×2
Bucket pin 1.7×3 Idler 19×2
Swing post 59 Adjust cylinder 18×2
Swing post pin 6.5 Track roller 6.8×6
Swing frame 325 Carrier roller 2.5×2
Hydraulic oil tank 35 Sprocket 6.5×2
Fuel tank 18 Turning motor 22
Engine cover(A) 31 Drive motor 36×2

Unit: kgf

Engine cover(B) 13.5 Console box 9×2
Counter weight 150 Engine 135
Guard(R)(L) 35×2 Radiator 6
Guard(Center) 10.5 Battery 22
Tops roof 90 Battery cover 3
Operator cabin 165 Swivel joint 21
Boom cylinder 28 Control valve 27
Arm cylinder 28 Pump 23
Bucket cylinder 23 Seat plate 14

2-6

2-5 Oil and grease supply points

Arm cylinder rod pin

Bucket cylinder head pin

Bucket link pin

Bucket cylinder rod pin

Bucket pin

Boom cylinder rod pin

Boom cylinder head pin

Dozer cylinder rod pin

Dozer joint pin

Boom arm joint pin

Arm cylinder head pin

Fuel tank

Hydraulic tank

Engine

Travel motor

Track roller

Adjust cylinder

Dozer cylinder head pin

Swing cylinder
rod pin

Swing post pin

Front idler

Slew gear

Swing cylinder
head pin

Boom joint pin

Slew bearing

2-7

2-6 List of lubrication

Name

Engine cooling water
Fuel tank

(effective capacity)
Engine lubricating oil

Travel motor
(reduction gear)

Hydraulic tank
Track roller (1 piece)
Front idler (1 piece)

Quantity of oil/water

5.5
42

4.5

600 cc

50.5

100 cc

80 cc

Genuine oil

Be sure to use Castrol Hyspin 46.

Table of recommended Lubricants

Type of oil according to ambient condition

-10°C~40°C -20°C~0°C

Soft water (antifreeze is mixed in water)
Diesel fuel with freezing point below -7°C

SAE 10W-30

SAE 30-CD

ISO VG 46
SAE 30-CD
SAE 30-CD

No. LUBRICANT SHELL MOBIL

1 Engine Oil Myrina oil 15W-40 Delvac Super15W-40
2 Gear Oil
3 Hydraulic Oil ISO VG 46 (equivalent) ISO VG46 (equivalent)
4 Cup Grease Alvinia 2 Mobilux 2
5 Anti Freeze Anti Freeze Anti Freeze
6 Diesel Fuel — —

*The engine oil SAE-CD 15W=40 or equivalent at the time of shipment is used for the
lubricating oil for slewing and travelling speed reducer.

Spirax Heavy Duty 140

Mobilub HD 85W-140

Cooling water (antifreeze)

*To prevent the cooling system from freezing, add antifreeze to the cooling water.
Replace the cooling water after 1 year from its delivery, because the effect will decrease.
*Use "Long-life coolant" for the antifreeze.
*Mixing ratio of antifreeze.

Temperature -5°C -10°C -15°C -20°C -25°C -30°C

antifreeze ratio

Engine inside capacity Radiator capacity Reserve tank capacity Total

2.5 2.4 0.6 5.5

1.7 2.2 2.7 3.1 3.5 3.8

2-8

2-7 When to repair

It is difficult to judge when to perform periodic inspections, maintenance and repairs.
Although the wearing rate of each component differs depending on the grade of daily
inspection, the skill in machine operation, the working conditions, the quality of used
lubricating oil, the frequency of oil replacement, the quality of land to be dug, the digging
rate, the schedule for maintenance and repairs should be decided considering the state
of engine, the indication of the hour meter, the degree of wear in each part, the state of
hydraulic system, your experience and data.

2-7-1 Category of maintenance

Prestart-up inspection
Maintenance after the first

25 service hours
Maintenance after the first

50 service hours
Maintenance after the first

100 service hours
Maintenance after the first

250 service hours
Maintenance after the first

300 service hours
Maintenance after the first

500 service hours
Maintenance after the first

1,000 service hours
Maintenance after the first

2,000 service hours

Execute every day before beginning
operation

Execute every 25 hours by the hour
meter

Execute once a week (every 50
hours by the hour meter)

Execute every 100 hours by the
hour meter

Execute every 250 hours by the
hour meter

Execute every 300 hours by the
hour meter

Execute every 500 hours by the
hour meter

Execute every 1,000 hours by the
hour meter

Execute every 2,000 hours by the
hour meter

2-9

2-7-2 Maintenance procedure

Inspection and
maintenance item

Engine oil pan

1

Engine oil filter

750100 250 500 1,000

Check oil
level

Replace the
engine oil
(New
machine only)

Replace the
cartridge
(New
machine only)

Inspection and maintenance interval (hours)

Replace the
engine oil

Replace the
cartridge

Clean

Fuel filter

2

Engine valve

3

clearance

Fan belt

4

Fuel tank

5

Radiator (sub-tank)

6

Radiator fin
Air cleaner

7

Hydraulic oil tank

8

Hydraulic line filter

9

Hydraulic suction
filter

10

Bucket teeth and

11

others
Slew bearing

12

Inspect crawler

13

tension(grease
cylinder) and
grease the crawler

Battery liquid

14

amount and
specific gravity

Inspect each body

15

part for loosening
and damage

Each lever and

16

instrument
Lubricating oil of

slew/travelling
reduction gear

17

Electrical wiring

18

Water and oil
leakage in each

19

body part
Inspect and grease

20

attachment
PTO filter element

21

Check and
adjust

Check oil
level

Check water
level

Check oil
level

Inspect

Check and
adjust

Check and
tighten

Inspect

Inspect
Inspect

Inspect
attachment

Inspect and
adjust (New
machine only)

Drain water
and sediment,
clean strainer

Check and
clean

Inspect and
grease

Inspect, clean
and supply
distilled water

Check and
clean

Check and
clean

Replace the
cartridge
(New
machine
only)

Clean the
element
(New
machine
only)

2-10

Drain water
and sediment

Replace the
element

Replace the
element

Inspect and
adjust

Replace and
clean

Replace the
element

Replace the
cartridge

Replace the
element

Replace oil
(after the first
500 service
hours only for
a new
machine)

Replace oil

Replace oil

2-7-3 Prestart inspections

(1)Prestart inspections

Item

Engine oil pan

1

Fuel tank

2

Radiator

3

Each oil/grease

4

supply point
Inspect each body

part for looseness

5

and damage
Each lever and

6

instrument
Hydraulic oil tank

7

Bucket teeth and

8

others

Content

Check oil level
Check fuel level

Check water level

Oil and grease
Looseness, removal,

water and oil leakage
Operation check

Check oil level

Wear

Remarks
Before starting operation
Check that the fuel level is

above the center of level
gauge.

Check that the amount of water
in sub-tank is within a specified
level.

Refer to page 2-6

Refer to tightening torque list.
Whether abnormal operation

exists or not
Add oil if its level falls below the

specified level. (Be careful of
the position of machine.)

Check whether the
replacement of parts is
necessary or not.

9

Electrical wiring

10

Fan belt

(2)Post opertaion inspections

Item

Each body part

1

Fuel tank

2

Cooling water

3

Looseness and tears
Check and adjust

Content

Clean, check for water
and oil leaks.
Looseness, failure, etc.

Fuel supply
Drain

Loosened terminal, torn
covering, etc.

10mm(0.4”) to 12mm(0.5”)
sag at the center

Remarks
Treatment of the part where

cleaning was not sufficient
such as dirt sticking to the
body or muddy water
remaining on the body.

Add fuel
Only when the danger of

freezing exists

2-11

Tightening torque list:

In the present inspection, always check for loosened bolts or nuts and correctly tighten
them according to the following tightening torque list.

N-m

Tightening torque of the bolt and nut (Body)

Material 8.8 10.9 12.9

Size N.mN

.

mN
M6 12.5 16 20
M8 30 39 45

M10 62 72 80
M12 100 120 130
M14 160 195 220
M16 250 305 340

N-m

PT screw

Tightening torque of the hydraulic pipings

PF screw

Torque

Torque

N.m

Size

Size

.

m

N.m

1

—

4
3

—

8
1

—

2
3

—

4
1
1

1—

4
1

1—

2

36

55

86

130

195

300

400

1

—

4
3

—

8
1

—

2
3

—

4
1

27-30

47-52

57-63

108-120

126-140

2-12

2-7-4 Maintenance every 50 service hours

Engine oil pan

1

Engine valve

3

clearance

Fuel tank

5

Radiator fin

Slew bearing

6

Battery

12

Battery

14

Each oil/grease

20

supply point

Item

Content

Replace engine oil
and filter

Inspect and adjust
Drain sediment and

water
Clean the strainer

Clean the fins

Inspect and grease

Liquid quantity

Specific gravity

Clean

Oil and grease

Remarks

Only for a new machine. After
this, every 250 service hours

Only for a new machine. After
this, every 500 service hours

Remove the drain plug on the
lower part of the tank

Wash strainer with diesel fuel
Dust sticking to the fin affects

the cooling effect and causes
overheating

Always grease the machine
after it is used in water

Whether the liquid level is
proper or not. If short, add
distilled water

1.26 when fully charged; 1.20
when discharged (Recharge
the battery when 1.20.)

Clean each part, brush and
connect terminal and apply
grease

Refer to page 2-7

2-13

2-7-5 Maintenance every 100 service hours

Item

Fuel filter

2

Air cleaner

7

9

Hydraulic line filter
Hydraulic suction

10

filter

Content

Clean the element
Clean the dust cover,

clean or replace the
element

Replace the cartridge
Clean the element

2-7-6 Maintenance every 250 service hours

Content

Replace the engine oil

Replace the cartridge
Drain water and

sediment

Engine oil

1

Engine oil filter
Hydraulic oil tank

8

Item

Remarks

After cleaning, open the cock
to vent air

Check also for a loosened band
Only for a new machine. After

this, every 500 service hours
Only for a new machine. After

this, every 500 service hours

Remarks

Remove the drain plug on the
lower part of the tank. (After
50 service hours for a new
machine)

After 50 service hours for a new
machine

After air is vent, loosen the
drain plug

Lubricating oil of
slew and travelling

17

reduction gears

Replace lubricating oil

2-7-7 Maintenance every 500 service hours

Fuel filter

2

Engine valve

3

clearance

6

Radiator

7

Air cleaner

9

Hydraulic line filter
Hydraulic suction

10

filter

Item

Replace the element
Check valve clearance

Replace cooling water
and clean the radiator

Replace the element
Replace the cartridge

Clean the element

Content

Replace oil after the first 200
service hours. Every 1,000
service hours after this (Refer
to Table of Oil/Grease Supply
Points)

Remarks
Clean the inside of bowl
Clearance between the valve

and the rocker
Remove the drain plug, clean

the radiator and add water to
the sub-tank up to the specified
level.

After 100 service hours for a
new machine

2-14

2-7-8 Maintenance every 1,000 service hours

Item
Engine oil pan

1

Hydraulic oil tank

8

Lubricating oil of

12

slew and travelling
reduction gears

Content
Clean engine oil pan
Replace the hydraulic

oil and clean the oil
tank

Replace the lubricating
oil

2-7-9 Maintenance every 2,000 service hours

Content

15

Item
Track roller

Replace

Table of Oil/Grease Supply Points

No.

1

2
3

Oil/Grease Supply
Point

Travel motor

Track roller
Front idler

Specified oil
(genuine part)

API Classification
CD Class SAE30

Quantity

600 cc

100 cc

80 cc

Remarks

Clean the inside of the tank
Refer to Table of Oil/Grease

Supply Points. (For new
machine, every 200 service
hours)

Remarks

Time

Every 1,000 service
hours (At first, replace
after the first 500
service hours)

Every 2,000 hours
Every 2,000 hours

2-15

2-8 Hydraulic circuit diagram

2-16

Item Robex 28-7
Boom cylinder ø75×ø40×564 st
Arm cylinder ø75×ø40×510 st
Bucket cylinder ø70×ø45×417 st
Swing cylinder ø65×ø40×627 st
Dozer cylinder ø75×ø40×125 st
Slew motor PCR-1B-05A-P-8446Z1
Travel motor PHV-250-37-1-8761A

Item Robex 28-7

P1 16.0 cc/rev
P2 16.0 cc/rev

Pump

capacity

P3 10.5 cc/rev

P1 20.6 MPa

Main
relief

P2 20.6 MPa
P3 17.2 MPa

Pressure

Pump

flow rate

Engine

Port relief 23.5 MPa

Unload (pump) 2.9 MPa

Slew 13.2 MPa

Q1 33.6 /min
Q2 33.6 /min
Q3 22.1 /min

Type S3L2

Constant output 17.7 kW (24.1 ps)

Speed 2,100 min

-1

Torque 85 N.m/1,800 min

-1

2-17

3ATTACHMENT

CONTENTS

3-1 Standard of maintenance

3-1-1 Attachment

3-2 Inspection and adjustment

3-2-1 Measuring the fall of the attachment of its

own weight

3-2-2 Measuring the speed of the attachment

cylinder

3-1 Standard of maintenance

3-1-1 Attachment

13

11

14

12

1

10

8

9

7

6

4

5

15

2

A

b

1. Swing cylinder
head

b

16

17

a

B

2. Swing cylinder
rod

3

a

b

a

b

C

D

3. Swing post
bracket and
swing post

a

b

a

a

b

E
F

G

4. Boom joint 5. Boom cylinder
head

3-1

H

6. Boom cylinder
rod

a

b

a

b

I

J

a

b

K

L

7. Arm cylinder
head

M

10. Bucket cylinder

head

b

8. Arm cylinder

9. Boom/arm joint

rod

a

a

a

b

N
O

11. Bucket cylinder
rod

a

b

P

Q

12. Bucket/dump
link joint

a

b

b

R
S

13. Arm/bucket link
joint

W

16. Dozer cylinder
rod

T

U

14. Arm/bucket

V

15. Dozer joint

a

b

joint

a

a

b

X

b

17. Dozer cylinder
head

3-2

Unit: mm(in)

No.

Item

A

Swing cylinder head pin and head bracket

B

Swing cylinder head pin and the boss of head bracket
Swing cylinder rod pin and swing post

C

Swing post pin and bush

D

Swing post pin and swing post bracket

E

Boom joint pin and bush

F

Boom joint pin and swing post

G

Boom cylinder head pin and swing post

H

Boom cylinder rod pin and boom

I

Arm cylinder head pin and boom

J

Arm cylinder rod pin and arm

K

Basic Dimension

ø34.7(1.37")

ø35(1.4")
ø35(1.4")
ø60(2.4")
ø60(2.4")
ø40(1.6")
ø40(1.6")
ø40(1.6")
ø40(1.6")
ø35(1.4")
ø35(1.4")

Allowable Clearance

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

Boom/ arm joint pin and bush

L

Boom/ arm joint pin and boom

M

Bucket cylinder head pin and arm

N

Bucket cylinder rod pin and dump link

O

Bucket cylinder rod pin and bucket link

P

Bucket pin and bush

Q

Bucket pin and bucket

R

Bucket link pin and bush

S

Bucket link pin and bucket link

T

Dozer joint pin and frame

U

Dozer cylinder head pin and dozer

V

Dozer cylinder rod pin and frame

W

ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")
ø35(1.4")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

1.0(0.04")

3-3

Unit: mm(in)

No.

Clearance between swing

1

cylinder head and swing post
Clearance between swing

2

cylinder rod and head bracket
Clearance between swing

3

post and frame
Clearance between boom

4

and swing post
Clearance between boom

5

cylinder head and swing post
Clearance between boom

6

cylinder rod and boom
Clearance between arm

7

cylinder head and boom
Clearance between arm

8

cylinder rod and arm
Clearance between boom

9

and arm

Item

Criterion

ab

53(2.1") 50(2.0") 2.0~3.5(0.08"~0.14")

51(2.0") 50(2.0")

215(8.46") 213(8.39")

173.5(6.8") 172.5(6.8") 1.0~3.5(0.04"~0.14")

51(2.0") 50(2.0")

51(2.0") 50(2.0")

51(2.0") 50(2.0")

51(2.0") 50(2.0")

130.5(5.14") 129(5.07")

Standard
clearance

0.5~2.0(0.02"~0.08")

2.0~3.3(0.08"~0.13")

1.0~2.5(0.04"~0.10")

1.0~2.5(0.04"~0.10")

1.0~2.5(0.04"~0.10")

1.0~2.5(0.04"~0.10")

1.5~3.0(0.06"~0.12")

Part Number Dimension

NBU3-00020 ø36×t0.5
NBU3-00021 ø36×t1.0

MBU3-00022 ø41×t0.5
MBU3-00023 ø41×t1.0

MBU3-00020 ø36×t0.5
MBU3-00021 ø36×t1.0

〃

〃

〃

〃

Spacer

〃〃

〃

〃〃

〃

〃

〃

Clearance between bucket

10

cylinder head and arm
Clearance between bucket

11

cylinder rod and dump link
Clearance between dump link

12

and bracket
Clearance between arm and

13

bucket link
Clearance between arm and

14

bucket
Clearance between dozer

15

and frame
Clearance between dozer

16

cylinder rod and frame
Clearance between dozer

17

cylinder head and dozer

51(2.0") 50(2.0")

51(2.0") 50(2.0")

135(5.3")

135(5.3") 134.5(5.3")0.5~1.0(0.02"~0.04")

135.5(5.3")

32(2.1") 30(2.0") 1.5~4.0(0.06"~0.16")

51(2.0") 50(2.0") 1.0~2.0(0.04"~0.08")

51(2.0") 50(2.0") 1.0~2.0(0.04"~0.08 ")

134.5(5.3")

134.5(5.3")1.0~1.5(0.04"~0.06")

1.0~2.5(0.04"~0.10")

1.0~2.5(0.04"~0.10")

0.5~1.0(0.02"~0.04")

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3-4

3-2 Inspection and adjustment

3-2-1 Measuring the natural fall of the attachment

1. Measuring the location of the attachment
Set the temperature of the hydraulic oil to 50±5°C. Adjust the height of arm/bucket joint
so that it equals that of the boom joint. Then, retract the dozer cylinder to the minimum
length and stop the engine.

2. Measurement
Draw a reference line on the cylinder head with a Magic Marker and measure the
length from the line to the cylinder tube. Measure the length again 3 minutes later.
Then record the difference in the length

Unit: mm (or less)

Cylinder name Standard value Allowance
Boom cylinder 13 26

Arm cylinder 13 26
Bucket cylinder 8 16
Dozer cylinder 7 14

Make 1 and 2 the same height.

W: Weight About: 110 kg

Arm cylinder

Bucket cylinder

Boom cylinder

Arm/bucket joint...2,

Boom joint...1,

Mark: Direction of cylinder movement

Dozer cylinder

3-5