LGMG T72J User manual

△
!WARNING
Operators and maintenance
personnel must read and
understand this manual before
operating and maintaining this
machine, otherwise it may lead to
casualties! This manual shall be
properly kept for reference and
check by relevant personnel.
LINGONG HEAVY MACHINERY CO., LTD.
Service Manual
T72J
Telescopic boom Mobile
Elevating Work Platform

Telescopic boom Mobile Elevating Work Platform
Service Manual
880*1230 mm Format: 16, Prints: 8
1st edition in May 2022 1st printing in May 2022
LINGO N G HEAVY MACHINE R Y CO . , LTD.
Address: Floor 12, Building 3, Lushangguo Aocheng, No. 9777, Jingshi Road, Lixia District,
Jinan City, Shandong, China.
Tel: [phone]
Web: www.lgmg.com.cn
Technical service: 86-4009666569
Parts sales: 86-0531-67605016

Service Manual of Telescopic boom Mobile
Elevating Work Platform
II
Contents
Contents..................................................................................................................................................... II
Foreword ...................................................................................................................................................VI
Safety notices...........................................................................................................................................VII
Chapter I Safety and environment............................................................................................................. 1
1.1 Terms and definitions........................................................................................................................ 3
1.2 Compliance....................................................................................................................................... 3
1.3 Before starting the repair.................................................................................................................. 3
1.4 Requirements for work site............................................................................................................... 3
1.5 Maintenance and repair safety specification.................................................................................... 4
1.6 Intended purpose.............................................................................................................................. 5
1.7 Description........................................................................................................................................ 5
Chapter II Product introduction .................................................................................................................. 7
2.1 Machine parameters......................................................................................................................... 9
2.2 Specification and tightening torque of nuts and bolts......................................................................11
Chapter III Repair..................................................................................................................................... 13
3.1 Description...................................................................................................................................... 15
3.2 Platform component ....................................................................................................................... 15
3.2.1 Assembly of platform assembly...................................................................................................... 15
3.2.2 Removal of platform assembly....................................................................................................... 16
3.2.3 Assembly of protective mount........................................................................................................ 16
3.2.4 Assembly of arc-shaped protective cover...................................................................................... 16
3.2.5 Assembly of file box and tool box................................................................................................... 17
3.2.6 Assembly of door lock .................................................................................................................... 17
3.2.7 Assembly of foot switch.................................................................................................................. 17
3.2.8 Assembly of PCU ........................................................................................................................... 17
3.2.9 Assembly of platform valve block................................................................................................... 18
3.2.10 Assembly of buffer rubber mount................................................................................................. 18
3.2.11 Assembly of platform support ...................................................................................................... 18
3.3 Jib assembly................................................................................................................................... 18
3.3.1 Assembly of jib structural parts ...................................................................................................... 18
3.3.2 Lowering and assembly of jib......................................................................................................... 18
3.3.3 Removal of jib................................................................................................................................. 19
3.3.4 Fly jib cylinder assembly................................................................................................................. 20
3.3.5 Removal of the fly jib cylinder......................................................................................................... 20
3.3.6 Removal of saddle swing cylinder.................................................................................................. 21
3.3.7 Assembly of load cell...................................................................................................................... 21
3.3.8 Limit block assembly ...................................................................................................................... 21
3.3.9 Assembly of swing motor mounting bracket................................................................................... 21
3.3.10 Assembly of upper leveling cylinder ............................................................................................ 22

Service Manual of Telescopic boom Mobile
Elevating Work Platform
III
3.3.11 Removal of upper leveling cylinder.............................................................................................. 22
3.4 Cable carrier assembly................................................................................................................... 23
3.4.1 Assembly of cable carrier............................................................................................................... 23
3.4.2 Removal of cable carrier................................................................................................................. 24
3.5 Boom frame assembly.................................................................................................................... 26
3.5.1 Assembly of boom frame................................................................................................................ 27
3.5.2 Boom frame removal...................................................................................................................... 28
3.5.3 Subassembly of telescopic cylinder ............................................................................................... 30
3.5.4 Assembly of telescopic cylinder ..................................................................................................... 31
3.5.5 Removal of telescopic cylinder....................................................................................................... 33
3.5.6 Assembly of luffing cylinder............................................................................................................ 34
3.5.7 Removal of the luffing cylinder....................................................................................................... 35
3.5.8 Assembly of lower leveling cylinder ............................................................................................... 36
3.5.9 Removal of lower leveling cylinder................................................................................................. 37
3.5.10 Rope............................................................................................................................................. 37
3.6 Transmission component ............................................................................................................... 39
3.6.1 Installation of flywheel coupling...................................................................................................... 39
3.6.2 Removal of flywheel coupler .......................................................................................................... 39
3.7 Variable displacement pump.......................................................................................................... 39
3.7.1 Assembly of open variable displacement pump............................................................................. 39
3.7.2 Removal of open-type variable displacement pump...................................................................... 39
3.7.3 Walking variable displacement pump assembly ............................................................................ 40
3.7.4 Removal of walking variable displacement pump.......................................................................... 41
3.8 Hydraulic oil tank, fuel tank............................................................................................................. 41
3.8.1 Assembly of hydraulic oil tank........................................................................................................ 41
3.8.2 Removal of hydraulic oil tank ......................................................................................................... 43
3.8.3 Fuel tank assembly......................................................................................................................... 43
3.8.4 Fuel tank removal........................................................................................................................... 44
3.9 Axle assembly................................................................................................................................. 44
3.9.1 Assembly of floating cylinder.......................................................................................................... 44
3.9.2 Removal of floating cylinder........................................................................................................... 44
3.9.3 Assembly of steering cylinder......................................................................................................... 45
3.9.4 Removal of steering cylinder.......................................................................................................... 45
3.9.5 Subassembly of walking reducer.................................................................................................... 45
3.9.6 Subassembly of walking motor....................................................................................................... 46
3.9.7 Assembly of steering connecting disc............................................................................................ 46
3.9.8 Removal of the reducer.................................................................................................................. 46
3.9.9 Assembly of wheel.......................................................................................................................... 47
3.9.10 Removal of wheel......................................................................................................................... 47
3.10 Assembly of rotary table................................................................................................................. 47

Service Manual of Telescopic boom Mobile
Elevating Work Platform
IV
3.10.1 Lowering and assembly of rotary table........................................................................................ 47
3.10.2 Lowering and assembly of center slewing joint........................................................................... 47
3.10.3 Lowering and assembly of slewing reducer................................................................................. 48
3.10.4 Removal of slewing reducer......................................................................................................... 48
3.10.5 Assembly of slewing mechanism guard plate.............................................................................. 49
3.11 Other component............................................................................................................................ 49
3.11.1 Assembly of travel switch............................................................................................................. 49
3.11.2 Assembly of DC power switch ..................................................................................................... 49
3.11.3 Assembly of emergency power unit............................................................................................. 49
3.11.4 Assembly of tilt sensor................................................................................................................. 50
3.11.5 Warning lamp assembly............................................................................................................... 50
3.12 Valve............................................................................................................................................... 51
3.13 Bleeding of cylinder........................................................................................................................ 54
3.13.1 Bleeding of walking variable displacement pump and gear pump.............................................. 54
3.13.2 Bleeding of slewing reducer......................................................................................................... 54
3.13.3 Bleeding of walking motor............................................................................................................ 54
3.13.4 Bleeding of steering cylinder........................................................................................................ 54
3.13.5 Bleeding of boom luffing cylinder and lower leveling cylinder..................................................... 54
3.13.6 Bleeding of boom telescopic cylinder .......................................................................................... 54
3.13.7 Bleeding of fly jib luffing cylinder and upper leveling cylinder ..................................................... 55
3.13.8 Bleeding of platform swing cylinder............................................................................................. 55
3.13.9 Bleeding of floating cylinder......................................................................................................... 55
Chapter V Commissioning........................................................................................................................ 57
4.1 Safety notices................................................................................................................................. 59
4.2 Commissioning process................................................................................................................. 59
4.2.1 Pick-up inspection .......................................................................................................................... 59
4.2.2 Liquid level detection...................................................................................................................... 59
4.2.3 Clearance detection........................................................................................................................ 60
4.2.4 Start test.......................................................................................................................................... 60
4.2.5 Basic operation test of GCU........................................................................................................... 61
4.2.6 Basic operation test of platform control unit................................................................................... 63
4.2.7 Drive enable system test................................................................................................................ 65
4.2.8 Steering pressure test..................................................................................................................... 65
4.2.9 Slewing pressure test..................................................................................................................... 66
4.2.10 Walking pump overflow pressure test.......................................................................................... 66
4.2.11 Function pump overflow pressure test......................................................................................... 66
4.2.12 Floating test of machine............................................................................................................... 67
4.2.13 Calibration of rated load............................................................................................................... 67
4.2.14 1.1 times rated load test............................................................................................................... 67
4.2.15 1.25 times load test...................................................................................................................... 67

Service Manual of Telescopic boom Mobile
Elevating Work Platform
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4.2.16 Large rated load (450) test........................................................................................................... 68
4.2.17 Settlement test............................................................................................................................. 68
4.2.18 Lifting height test.......................................................................................................................... 69
4.2.19 Operation time test....................................................................................................................... 69
4.2.20 Driving speed (high speed) test................................................................................................... 71
4.2.21 Braking distance test.................................................................................................................... 71
4.2.22 Limit driving speed test................................................................................................................ 71
4.2.23 Tilt sensor test.............................................................................................................................. 72
4.2.24 Climbing test (45%)...................................................................................................................... 72
Chapter V Maintenance............................................................................................................................ 73
5.1 Compliance..................................................................................................................................... 75
5.2 Inspection of slewing ring............................................................................................................... 75
5.3 Inspection of arm rod wear washer................................................................................................ 75
5.4 Inspection of rope........................................................................................................................... 76
5.5 Check the oil level in the reducer................................................................................................... 76
5.6 Inspection of hydraulic oil and filter................................................................................................ 77
5.7 Maintenance of Deutz engine......................................................................................................... 78
5.7.1 Check of engine oil level ................................................................................................................ 78
5.7.2 Replacement of engine oil and filter............................................................................................... 78
5.7.3 Check for fuel leakage.................................................................................................................... 79
5.7.4 Draining or replacement of fuel filter.............................................................................................. 80
5.7.5 Check of engine air filter................................................................................................................. 81
5.7.6 Cleaning or replacement of air filter............................................................................................... 81
5.7.7 Check of coolant level .................................................................................................................... 81
5.7.8 Adding or replacement of engine coolant....................................................................................... 81
5.7.9 Check the engine belt..................................................................................................................... 82
5.8 Scheduled maintenance................................................................................................................. 83
5.9 Engine fault diagnosis .................................................................................................................... 84
Chapter VI Annex..................................................................................................................................... 91
6.1 System DTC ................................................................................................................................... 93
6.2 Description of harness wire size..................................................................................................... 95
6.2.1 Main harness.................................................................................................................................. 95
6.2.2 Valve block harness........................................................................................................................ 96
6.3 Schematic diagram......................................................................................................................... 98
6.3.1 Electrical schematic diagram.......................................................................................................... 98
6.3.2 Hydraulic schematic diagram......................................................................................................... 99
6.4 Symbols of common hydraulic parts ............................................................................................ 100
6.5 Schematic diagram of symbols of common electrical components............................................. 107

Service Manual of Telescopic boom Mobile
Elevating Work Platform
VI
Foreword
Thanks for purchasing the products produced by Lingong Heavy Machinery Co., Ltd. This Manual
introduces the technical parameters and maintenance and adjustment data of T72J straight-arm lifting
platform, and explains the troubleshooting and repair process for qualified maintenance personnel.
The relevant content in this manual is correct at the time of publication. Due to continuous improvement
of product structure and performance, we may change the description on design, operation and
maintenance without prior notice. For the latest machine information and questions about this manual,
please consult our company. At the same time, we encourage readers to give error feedback to Lingong
Heavy Machinery Co., Ltd. and make suggestions for improvement. All suggestions will be carefully
considered in the future publishing and printing of this manual.
The copyright of this manual is owned by Lingong Heavy Machinery Co., Ltd.. No reproduction or
reprinting is allowed without the written permission of our company.
△
!WARNING
Only specially trained and qualified personnel can operate, repair and maintenance this
machine.
Incorrect operation, maintenance and repair are in danger and may result in personal
injury or death.
Before operating or maintaining this machine, the operator shall read this manual
carefully at first. Do not operate, maintain or repair this platform without reading and
understanding this manual.
Please load the machine in strict accordance with the rated load. The user shall be
responsible for any consequences caused by overload or modification without
permission.
The operation regulations and prevention provided by this manual are only applicable
for the purposes intended for this machine. For operations outside the specifications
but not prohibited, make sure that the operation will not cause harm to you or others.

Service Manual of Telescopic boom Mobile
Elevating Work Platform
VII
Safety notices
Operators shall understand and abide by the current national and local safety provisions. If there are no
national or local provisions, the safety instructions in this manual shall apply.
Most of the accidents are caused by failure to comply with the operation and maintenance regulations of
machine. In order to avoid accidents, please read, understand and observe all warning requirements and
precautions in this manual and on the machine before operation and repair. Failure to comply with the
instructions and safety rules in this Manual and on the machine will result in death or serious injury.
Since it is not possible to foresee all possible dangers, the description on safety in this manual and on
the machine may not include all safety precautions. If steps and actions not recommended in this manual
are used, you must ensure the safety of yourself and others and prevent damage to the machine. If you
are not sure about the safety of some operations, please contact our company or dealer.
Most operations require basic mechanical, hydraulic and electrical skills, and some operations require
specialized skills, tools, lifting equipment and suitable workshops. In these cases, we strongly
recommend that the maintenance and repair shall be carried out at the service center of the dealer
authorized by Lingong Heavy Machinery Co., Ltd.
The prevention measures for maintenance and repairing given in this manual apply only when the
machine is used for the specified purposes. If the machine is used for the purpose not listed in this
manual, then our company will not assume any safety liability, and the safety liability in such operations
shall be borne by the user and the operator.
Under no circumstances shall the operations prohibited in this manual be carried out.
The following marker words are used to identify safety information in this manual:
△
!DANGER-indicating dangers that, if not avoided, will lead to serious injury or
death. This term is also used for cases that, if not avoided, will cause serious
damage to the machine.
△
!WARNING-indicating potential dangers that, if not avoided, will cause serious
injury or death. WARNING-indicating potential dangers that, if not avoided, will cause
serious injury or death.
△
! CAUTION - indicating cases that, if not avoided, may cause minor or
moderate injuries. This term is also used for cases , if not avoided, may
cause serious damage to the machine.

Service Manual of Telescopic boom Mobile
Elevating Work Platform
1
Chapter I Safety and environment

Service Manual of Telescopic boom Mobile
Elevating Work Platform
2