Yuchai YC20SR User manual

HYDRAULIC EXCAVATOR
YC20SR / YC18SR
U20 / U18
OPERATION MANUAL
GUANGXI YUCHAI HEAVY INDUSTRY COMPANY LIMITED

It is particularly important that the operator should read these instructions carefully in order to operate
and maintain the excavator safely and correctly. Otherwise accidents or damage may occur.
 Remember the safety procedures and proper use of the machine.
 Read and understand the instructions for the safe operation of the machine.
 Understand and be familiar with all safety signs on the machine.
 Make sure that nobody unrelated to the job is at the work site.
 Operators should have been trained in the safe operation of the machine before operating the
machine at the work site.
You are responsible for complying with relevant laws and regulations and following Yuchai Heavy
Industries' instructions on machine operation and maintenance.

CATALOGUE
1. Foreword ......................................................................................................................................................................... 1
1.1. To Users .................................................................................................................................................................. 1
1.2. Machine information ........................................................................................................................................... 2
1.3. Machine directions ............................................................................................................................................... 4
1.4. Machine components ........................................................................................................................................... 5
1.5. General Operation Information ......................................................................................................................... 6
1.5.1. Specified operations.................................................................................................................................... 6
1.5.2. Break-in ......................................................................................................................................................... 6
1.6. Safety-related information .................................................................................................................................. 6
1.7. Technical specifications ...................................................................................................................................... 8
1.7.1. Dimension paragauges ............................................................................................................................... 8
1.7.2. Working paragauges .................................................................................................................................. 9
1.7.3. Traveling mechanism .............................................................................................................................. 10
1.7.4. Hydraulic system ...................................................................................................................................... 10
1.7.5. Electric system .......................................................................................................................................... 10
1.7.6. Working condition ................................................................................................................................... 10
1.7.7. Interference ................................................................................................................................................ 11
2. Safety rules .................................................................................................................................................................. 12
2.1. General safety rules ........................................................................................................................................... 12
2.2. Safety labels and instructions ......................................................................................................................... 13
2.3. Safety equipment ............................................................................................................................................... 13
2.4. Security Signs ..................................................................................................................................................... 14
2.4.1. Classification of safety signs ................................................................................................................. 14
2.4.2. Location of safety Signs ......................................................................................................................... 15
2.4.3. Safety signs and descripton .................................................................................................................... 16
2.5. Workplace safety ............................................................................................................................................... 20
2.6. Safe Operations .................................................................................................................................................. 21
2.6.1. Start the engine ......................................................................................................................................... 21
2.6.2. Travel and Swinging ................................................................................................................................ 22

2.6.3. Safety rules when traveling .................................................................................................................... 23
2.6.4. Traveling or working on slopes ............................................................................................................ 23
2.6.5. Safe excavation operations ..................................................................................................................... 26
2.6.6. Tip and Skipping Prevention and Countermeasures ........................................................................ 30
2.6.7. Transportation and Handling ................................................................................................................. 31
2.6.8. Downtime maintenance .......................................................................................................................... 32
2.6.9. Fire, Explosion and Poisoning Prevention ......................................................................................... 33
2.6.10. Battery ......................................................................................................................................................... 35
2.6.11. Hydraulic system ...................................................................................................................................... 36
3. Introduction of Components .................................................................................................................................... 40
3.1. Control Consoles ............................................................................................................................................... 40
3.2. Safety locking components ............................................................................................................................. 41
3.3. Switch assembly ................................................................................................................................................ 42
3.4. Electronics Controls .......................................................................................................................................... 43
3.4.1. Key (start switch operation) ................................................................................................................... 43
3.4.2. Cigarette lighter ........................................................................................................................................ 44
3.5. Monitor ................................................................................................................................................................ 44
3.6. Work device s and Swing Controls ............................................................................................................... 45
3.7. Travel control ..................................................................................................................................................... 46
3.8. Throttle handle and stop handle ..................................................................................................................... 46
3.9. Driver's Seat ........................................................................................................................................................ 47
3.10. Seat belt ........................................................................................................................................................... 47
4. Operation Instructions ............................................................................................................................................... 49
4.1. Preparation before operating the machine ................................................................................................... 49
4.2. Engine Operation ............................................................................................................................................... 50
4.2.1. Check before starting the engine .......................................................................................................... 50
4.2.2. Starting the engine ................................................................................................................................... 51
4.2.3. After starting the engine ......................................................................................................................... 54
4.2.4. Shut down the engine .............................................................................................................................. 54
4.2.5. Check after turning off the engine ........................................................................................................ 55

4.3. Enter and exit the machine .............................................................................................................................. 55
4.4. Traveling .............................................................................................................................................................. 56
4.4.1. Safety principles for traveling ............................................................................................................... 56
4.4.2. Preparation for traveling ......................................................................................................................... 57
4.4.3. Travel forward........................................................................................................................................... 57
4.4.4. Travel backward ....................................................................................................................................... 58
4.4.5. Stop the machine ...................................................................................................................................... 58
4.5. Steering ................................................................................................................................................................ 59
4.5.1. Turning when the machine is stopped ................................................................................................. 59
4.6. Rotation ................................................................................................................................................................ 60
4.7. Working device Operations ............................................................................................................................. 60
4.7.1. Arm control ................................................................................................................................................ 60
4.7.2. Rotation control ........................................................................................................................................ 61
4.7.3. Boom control ............................................................................................................................................. 61
4.7.4. Bucket control ........................................................................................................................................... 61
4.7.5. Boom deflection control ......................................................................................................................... 61
4.7.6. Dozer blade control .................................................................................................................................. 61
4.8. Working on slope or water .............................................................................................................................. 62
4.8.1. Slope ............................................................................................................................................................ 62
4.9. Getting out of the Muddy Environment ....................................................................................................... 63
4.10. General Operations instruction .................................................................................................................. 64
4.10.1. Backhoe operation .................................................................................................................................... 64
4.10.2. Loading operation .................................................................................................................................... 64
4.10.3. Trenching operations ............................................................................................................................... 65
4.10.4. Backfilling or grading ............................................................................................................................. 65
4.10.5. Shake off the soil stuck in the bucket .................................................................................................. 65
4.10.6. Precautions for the use of related parts ............................................................................................... 65
4.11. Removal and installation of bucket .......................................................................................................... 66
4.12. Disassembly ................................................................................................................................................... 67
4.13. Parking............................................................................................................................................................. 68

4.14. After operation ............................................................................................................................................... 69
4.14.1. Check .......................................................................................................................................................... 69
4.14.2. Lock up ....................................................................................................................................................... 69
4.15. Loading and unloading and transportation .............................................................................................. 69
4.15.1. Safety rules ................................................................................................................................................ 69
4.15.2. Loading ....................................................................................................................................................... 70
4.15.3. Fixing the machine on the transport vehicle ...................................................................................... 72
4.15.4. Unloading from the transport vehicle .................................................................................................. 72
4.15.5. Lifting machine ......................................................................................................................................... 73
4.16. Operation in cold/hot climate ..................................................................................................................... 74
4.16.1. Operation in cold climate ....................................................................................................................... 74
4.16.2. Operating in hot weather ........................................................................................................................ 75
4.17. Storage of the machine ................................................................................................................................ 76
4.17.1. Preparation before storage ...................................................................................................................... 76
4.17.2. During storage ........................................................................................................................................... 77
4.17.3. Returning to work after storage ............................................................................................................ 77
4.18. Causes of technical failures and solutions .............................................................................................. 78
5. Maintenance ................................................................................................................................................................ 85
5.1. General knowledge of maintenance .............................................................................................................. 85
5.1.1. New machine break-in ............................................................................................................................ 85
5.1.2. Working in dusty sites ............................................................................................................................. 85
5.1.3. Oil and Filter ............................................................................................................................................. 85
5.1.4. Timer Readings ......................................................................................................................................... 86
5.1.5. Use genuine parts ..................................................................................................................................... 86
5.1.6. Waste disposal........................................................................................................................................... 86
5.1.7. Prevent objects from falling into the machine ................................................................................... 86
5.1.8. Periodic inspection and maintenance ................................................................................................... 87
5.1.9. Review after inspection and maintenance .......................................................................................... 87
5.2. Maintenance Summary ..................................................................................................................................... 88
5.2.1. Lubricant .................................................................................................................................................... 88

5.2.2. Fuel .............................................................................................................................................................. 88
5.2.3. Grease ......................................................................................................................................................... 88
5.2.4. Coolant ........................................................................................................................................................ 89
5.2.5. Filter element ............................................................................................................................................. 89
5.2.6. Hydraulic system ...................................................................................................................................... 89
5.2.7. Electrical System ...................................................................................................................................... 90
5.3. Wear and tear parts............................................................................................................................................ 90
5.4. Mandatory replacement parts.......................................................................................................................... 91
5.5. Oil selection table .............................................................................................................................................. 92
5.6. Tightening Torque ............................................................................................................................................. 93
5.6.1. Tightening torque for general parts ...................................................................................................... 93
5.6.2. Tightening torque for hydraulic Hoses ................................................................................................ 94
5.7. Periodic Inspection and Maintenance Table ............................................................................................... 96
5.8. General checking ............................................................................................................................................... 98
5.9. Engine Fuel System .......................................................................................................................................... 98
5.9.1. Oil level check and refueling ................................................................................................................. 98
5.9.2. Drain water and contaminants from the tank ..................................................................................... 99
5.9.3. Cleaning the fuel tank ............................................................................................................................. 99
5.9.4. Check the injection pressure .................................................................................................................. 99
5.9.5. Vent air from fuel circuit ...................................................................................................................... 100
5.9.6. Changing the fuel filter ......................................................................................................................... 100
5.9.7. Replace the fuel filter ............................................................................................................................ 101
5.10. Engine Cooling System ............................................................................................................................. 101
5.10.1. Check the coolant level ......................................................................................................................... 102
5.10.2. Check the condition of the rubber hoses and clamps ..................................................................... 102
5.10.3. Clean and inspect the radiator blades ................................................................................................ 103
5.10.4. Coolant replacement .............................................................................................................................. 103
5.10.5. Check the coolant concentration ......................................................................................................... 104
5.11. Engine Lubrication System ...................................................................................................................... 104
5.11.1. Oil level check ........................................................................................................................................ 105

5.11.2. Change the engine oil ............................................................................................................................ 105
5.11.3. Replace the engine oil filter element ................................................................................................. 106
5.11.4. Oil filter replacement ............................................................................................................................. 106
5.12. Engine air intake system ........................................................................................................................... 106
5.12.1. Cleaning of dust collection bin ........................................................................................................... 107
5.12.2. Clean the air filter element ................................................................................................................... 107
5.12.3. Replace the air filter element ............................................................................................................... 108
5.12.4. Check the air inlet pipe ......................................................................................................................... 108
5.13. Other engine maintenance......................................................................................................................... 108
5.14. Hydraulic system ........................................................................................................................................ 109
5.14.1. Check the oil level in the hydraulic oil tank .................................................................................... 110
5.14.2. Drain the water and dirt in the hydraulic oil tank ........................................................................... 111
5.14.3. Replace the hydraulic oil and clean the oil suction filter .............................................................. 111
5.14.4. Vent air from the hydraulic system .................................................................................................... 113
5.14.5. Replace the return oil filter element ................................................................................................... 115
5.14.6. Replace the pilot oil filter element ..................................................................................................... 116
5.15. Battery ........................................................................................................................................................... 117
5.15.1. Storage of battery ................................................................................................................................... 118
5.15.2. Charging of the battery ......................................................................................................................... 118
5.15.3. Installation of the battery ...................................................................................................................... 119
5.15.4. Battery maintenance .............................................................................................................................. 120
5.16. Speed Reducer ............................................................................................................................................. 120
5.16.1. Traveling reducer ................................................................................................................................... 121
5.16.2. Replace the lubricant (for each gearbox) .......................................................................................... 121
5.16.3. Check the tightening torque of the bolts connecting the travel reducer and the slewing
reducer 122
5.16.4. Check the solidity of the connecting bolts of the slewing reducer ............................................. 122
5.16.5. Tracks ........................................................................................................................................................ 122
5.17. Idler wheel and guide wheel ..................................................................................................................... 124
5.18. Lubrication ................................................................................................................................................... 124
5.19. Replacement of bucket teeth .................................................................................................................... 126

5.20. Flushing of the floor mat ........................................................................................................................... 127
6. Attachment Guide .................................................................................................................................................... 128
6.1. Safety issues ...................................................................................................................................................... 128
6.1.1. Safe operation of attachments ............................................................................................................. 129
6.2. Removing or installing attachments ............................................................................................................ 130
6.2.1. Attachment Installation/Removal Procedure ................................................................................... 130
6.3. Attachment Operation Guide ........................................................................................................................ 131
6.3.1. Hydraulic Hammer ................................................................................................................................. 132
6.4. Daily inspection of hydraulic hammer ....................................................................................................... 135
6.5. Quick coupler ................................................................................................................................................... 136
6.6. Grab Bucket ...................................................................................................................................................... 137
6.6.1. Installation of grab bucket .................................................................................................................... 137
6.6.2. Operation of the grab bucket ............................................................................................................... 138
6.6.3. Operation precasutions of the grapple ............................................................................................... 138
6.6.4. Maintenance of the grapple .................................................................................................................. 140
6.7. Drilling device .................................................................................................................................................. 140
6.7.1. Installation of drilling device ............................................................................................................... 140
6.7.2. Operation of the drilling unit ............................................................................................................... 141
6.7.3. Precautions for the operation of drilling device .............................................................................. 141
6.8. Backhoe bucket with scraper ........................................................................................................................ 142
6.8.1. Installation................................................................................................................................................ 142
6.8.2. Operation of the backhoe bucket ........................................................................................................ 143
6.8.3. Maintenance of the backhoe bucket ................................................................................................... 143

1
1. Foreword
1.1. To Users
Dear users.
Greetings!
Welcome to use Yuchai excavator and thank you for your great support to Yuchai business.
This manual is intended as a safety guide and for the proper use and maintenance of the
machine. Before starting and operating the machine for the first time and before servicing
the machine, please make sure to read and understand this manual carefully and fully
understand the safety procedures, operation and maintenance procedures.For easy access,
keep this manual in a safe place so it can be read regularly by qualified machine operators.
If this manual is lost, damaged or illegible, please order it immediately from our company
or dealer. When transferring the machine, please pass this manual along with it so the next
owner can use it properly.
Please entrust the overhaul and adjustment of the machine to Yuchai Heavy Industry's
dealer or service station, and use original parts and spare parts provided by our company. If
you use non- original parts or components, they may not have an obvious effect on the
machine at the time, but may cause problems later. Yuchai Heavy Industry will not
undertake the warranty service even if the machine breaks down during the warranty period
due to the use of non-original parts or components or the maintenance is done by
unauthorized organizations.
Based on the principle of "customer first", Yuchai Heavy Industry continuously improves
its products in order to provide the best possible products to customers, for which
improvements may be implemented at any time. For the products being sold at that time,
we do not replace the information and do not give any advance notice.
We sincerely hope that this machine will serve you better and create more value with your
proper use and careful care.

2
1.2. Machine information
When you need to know the basic information of the machine, you can view it in the
position shown in the picture.
 Machine information (Nameplate is located on the right front side of the upper machine)
 Engine Information
 Machine operation information (engine timer is located on the monitor in the right
joystick box)

3
Machine Archives
Fill in the form below with the VIN and engine number of your machine. You can provide
them to Yuchai when you need to purchase spare parts or request relevant information.
Please record these numbers and keep them together with the product certificate. If your
machine is stolen, you can submit them to police.
 MODEL：
 SERIAL NUMBER：
 ENGINE SERIAL NUMBER：
 DEALER：

4
1.3. Machine directions
The front, back, left, right, top and bottom on this manual refer to each direction of the
illustrated pictures.
Up
Down
Right
Front Back
Left

5
1.4. Machine components
1 Bucket 12 Tracks
2 Bucket Cylinder 13 Travel Reducer
3 Arm 14 Driving Roller
4 Arm Cylinder 15 Carrier Roller
5 Boom Cylinder 16 Chassis
6 Boom 17 Slew Ring
7 Cab 18 Idler
8 Hydraulic Tank 19 Boom Swing Cylinder
9 Fuel Tank 20 Dozer Blade Cylinder
10 Rear Panel 21 Boom Swing Knuckle
11 Upper Platform 22 Dozer

6
1.5. General Operation Information
1.5.1. Specified operations
This machine is mainly used for the following operations.
 Digging
 Trenching
 Loading
 Grading
Please refer to operation guide and attachment guide for detailed descriptions of the
operating principles.
1.5.2. Break-in
The machine has been fully adjusted and checked before delivery. If the machine is
operated at full load from beginning, it will accelerate the degradation of performance
and shorten the service life of the machine. Therefore, for the first 100 hours (the time
displayed on the gauge), please limit the load to 80% of the full load during break-in
period.
1.6. Safety-related information
Most of the accidents related to operation, inspection, maintenance and repair work are
caused by negligence of basic safety precautions and hazard prediction.
By anticipating the conditions where hazards may occur, accidents can be prevented.
Therefore, it is important to be aware of the location and type of hazards. (In order to do so,
operators must have the required training, skills, and tools.)
Read and understand all safety precautions, WARNINGs and accident prevention methods
described in this manual and on the machine. Otherwise you should never operate and
inspect the machine. If these WARNINGs are ignored, injury or death may result.
The safety instructions in this manual and the safety signs used on this machine distinguish
the level of danger that may occur by the following WARNINGs. Precautions to avoid
hazards are also included.
Danger: Indicates that if not avoided, the consequences of the hazard will result in death
or serious injury and is only applicable to the few occasions when the greatest danger
exists.

7
WARNING: Indicates that the consequences of the potential hazard may result in
death or serious injury if not avoided.
CAUTION: Indicates that the consequences of a potential hazard may result in a low
or moderate level of injury if not avoided, and may also be used to indicate unsafe
practices that may result in injury.
We cannot predict all hazards of operation, inspection, maintenance and repair in all
environments. Therefore, the WARNINGs indicated in this manual and on the machine do
not cover all situations. During operation, inspection, maintenance and repair operations
that are not covered in this manual, user is requested to follow the necessary safety
precautions. It is the responsibility of the user to take the necessary safety precautions.

8
1.7. Technical specifications
1.7.1. Dimension paragauges
Items Unit YC20SR（E20F51S）
Working weight Kg 2000（cabin, rubber track)
Bucket capacity m3 0.05
Engine model Yanmar 3TNV76-P
Engine power kw/rpm 14.5/2400
A Overall length (transportation status) mm 3750
B Total length of grounding 2650
C Working device height (to the top of boom) mm 1150
D Overall width mm 1080
E Over all height (transportation status) mm 2345
F Ground clearance of platform mm 465
G Min. ground clearance of chassis mm 145
H Tail slewing radius mm 700
I Track grounding length mm 1230
J Track length mm 1600
K Gauge mm 850/1170
L Width of chassis mm 1080/1400
M Width of track mm 230
O Height of engine hood mm 1265
P Length from slewing center to tail mm 700
Max. slewing speed Rpm 8.5~10.5
Traveling speed km/h 2 / 4

9
Specifications are subject to change without prior notice
1.7.2. Working paragauges
Items Unit YC20SR（E20F51S）
AA
Max. digging height
mm
36
00
BB
Max.
dumping height
mm
2
485
CC
Max. digging depth
mm
23
10
DD
Max. vertical digging depth
mm
19
20
EE
working device Min. slewing radius
mm
1690
FF
Max. digging radius on ground level
mm
4060
GG
Max. digging radius
mm
4125
HH
Max. lifting height of
dozer blade
mm
2
45
JJ
Maximum bulldozing depth
mm
245
Max. digging force of bucket
KN
15.5
Max. digging force of arm
KN
8.5
offset boom Max. left swing angle
o
55
offset boom Max. right swing angle
o
65

10
Specifications are subject to change without prior notice
1.7.3. Traveling mechanism
The traveling system is driven by hydraulic motor through multistage planetary reducer.
Traveling speed Gradeability
High speed 4 58%(30
o
)
Low speed 2
1.7.4. Hydraulic system
Load sensing hydraulic system.
Max. hydraulic flow rate: 61.6L/min （2200 rpm）
Working pressure: 24 Mpa (LS=21.5 Mpa, load compensated pressure difference 2.5
Mpa)
Slewing pressure: 9 Mpa
Auxiliary pipe 1 / Auxiliary pipe 2 pressure: 21 Mpa
Pilot pressure: 3.5 Mpa
Oil return filter: 10 μm
Oil intake filter: metal filter
1.7.5. Electric system
Voltage: 12V
Battery: 45 AH
1.7.6. Working condition
Temprature: -15~40oC

11
Humidity: <85%
Altitute: ≤1500m
Transportation and storage temprature: -15~40oC
1.7.7. Interference
Non-standard working devices may interfere with the boom cylinder or the lower cover
of the boom. When non-standard working devices are used , attention should be paid to
the angle between the boom and the boom when retrieving the bucket to prevent
interference with the boom cylinder and damage to the machine body.
The following are all the non-standard attachment work device s that we offer.
Buckets
Bucket attachments mounted directly on the boom
Bucket attachment with quick connector
Bucket attachment mounted on quick couple
Rock
breaker
Directly mounted on the boom
Crushing hammers mounted on quick couple
Auger
Auger mounted on the boom directly
Auger mounted on quick couple
Grab Grabs directly mounted on booms
If you buy a model with any of the above attachments, you need to pay attention to the
above mentioned issues.