JLG Telehandler 742 943 1043 1055 1255 Service Manual 3122552100 2025

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JLG Telehandler 742 943 1043 1055 1255 Service Manual 3122552100 2025
Size: 95.60 MB
Format: PDF
Language: English
Brand: JLG
Type of Machine: Telehandler
Type of Manual: Service Manual, Electrical and Hydraulic Diagrams
Model: JLG 742, 943, 1043, 1055, 1255 Telehandler
Part Number: 3122552100
Publication Date: 2025
Number of Pages: 688 Pages

Contents:
Cover Page
Effectivity Page
Read This First

Modifications​

Machine Configuration​

Safety

General (concept)​

1.1.1 Disclaimer​

1.1.2 Operation & Safety Manual​

Safety Information​

1.2.1 Safety Alert System and Signal Words​

Safety Hazards (task)​

1.3.1 Personal Hazards​

1.3.2 Equipment Hazards​

1.3.3 General Hazards​

1.3.4 Operational Hazards​

Safety Decals​

Machine Verification​

General Machine Information and Specifications

Specifications​

2.1.1 Maximum Travel Speed​

2.1.2 Boom Performance​

2.1.3 Cylinder Drift​

2.1.4 Steering Angle Specifications​

2.1.5 Battery​

2.1.6 Engine Performance Specifications​

2.1.7 Tires​

Machine Temperature Chart​

Serial Number Location​

Fluids and Lubrication​

2.4.1 General Information​

2.4.2 Hydraulic Oil​

2.4.3 Changing Hydraulic Oil​

2.4.4 Lubrication Specifications​

2.4.5 Fluids​

2.4.6 Capacities​

2.4.7 Lubrication Schedules​

ClearSky Smart Fleet​

2.5.1 General​

2.5.2 ClearSky Smart Fleet™ – Access Control​

Maintenance and Inspection Schedules

Machine Preparation, Inspection, and Maintenance​

3.1.1 Preparation, Inspection, and Maintenance​

3.1.2 Pre-Start Inspection​

3.1.3 Pre-Delivery Inspection​

Service and Guidelines​

3.2.1 General​

3.2.2 Safety and Workmanship​

3.2.3 Cleanliness​

3.2.4 Components Removal and Installation​

3.2.5 Component Disassembly and Assembly​

3.2.6 Pressure-Fit Parts​

3.2.7 Bearings​

3.2.8 Gaskets​

3.2.9 Bolt Usage and Torque Application​

3.2.10 Hydraulic Lines and Electrical Wiring​

3.2.11 Hydraulic System​

3.2.12 Lubrication​

3.2.13 Battery​

3.2.14 Welding on JLG Equipment​

Preventive Maintenance and Inspection Schedule​

3.3.1 Maintenance Schedule​

Pins and Composite Bearing Repair Guidelines​

3.4.1 Filament Wound Bearings​

Tires & Wheels​

3.5.1 Tire Inflation​

3.5.2 Tire Damage​

Brake Maintenance​

3.6.1 Park Brake Bleeding (Front Axle Only)​

3.6.2 Service Brake Bleeding​

3.6.3 Brake System Check​

3.6.4 Service Brake Test​

3.6.5 Brake Inspection​

3.6.6 Steering Angle Adjustment​

DEF Tank Inspection​

Boom Inspection and Maintenance​

3.8.1 Boom Wear Pads​

Hydraulic Filter Replacement​

3.9.1 Hydraulic Filter Removal and Installation​

Testing, Calibrations and Special Procedures

Special Tools​

4.1.1 Multimeter​

4.1.2 Thread Locking Compound​

4.1.3 Tools Catalog​

Testing Procedures​

4.2.1 Starter​

4.2.2 Alternator​

4.2.3 Fuel Level Sender​

Calibration Procedures​

4.3.1 Analyzer​

4.3.2 Boom Angle Sensor Calibration​

4.3.3 LSI System Calibration​

Special Procedures​

4.4.1 Emergency Boom Lowering Procedure​

4.4.2 Precision Gravity Lower System (PGLS)​

4.4.3 Towing a disabled machine​

4.4.4 Hydraulic Oil Tank​

4.4.5 Diesel Exhaust Fluid (DEF) System Cleaning (if equipped for ULS)​

4.4.6 Accumulators​

4.4.7 Hydraulic Pressure Settings and Adjustments​

4.4.8 Cylinder Pressure Checking​

4.4.9 Cylinder Drift Test​

4.4.10 Hydraulic Circuits​

4.4.11 Hydraulic Pressures​

4.4.12 Pressure Specification​

4.4.13 Boom Chain Adjustment - 742, 943, 1043​

4.4.14 Boom Chain Adjustment - 1055, 1255​

4.4.15 Boom Extend and Retract Chains​

4.4.16 Rear Axle Stabilization (RAS) System Test​

System Software

Load Stability Indicator (LSI)​

5.1.1 Load Stability Indicator​

5.1.2 LSI Sensor​

JLG Analyzer​

5.2.1 Machine Data Access​

5.2.2 JLG Hand Held Analyzer​

5.2.3 JLG Mobile Analyzer and ClearSky SmartFleet Bluetooth Analyzer​

5.2.4 PC Analyzer/Loglifter​

5.2.5 Analyzer Software (Version P26.0)​

Analyzer Software Accessibility​

5.3.1 Access Level​

5.3.2 Diagnostics​

5.3.3 Machine Set-Up (Software Version P26.0)​

5.3.4 Personalities (Software Version P26.0)​

5.3.5 Operator Tools (Software Version P26.0)​

5.3.6 Calibrations (Software version P26.0)​

Premium Display (If Equipped)​

5.4.1 Home Screen and Touch Screen Soft Buttons​

5.4.2 Main Menu​

5.4.3 Reprogramming Menu​

Reprogramming the Premium Display​

5.5.1 Software Installation​

5.5.2 Load Charts Programming​

ClearSky (CS550) Configuration and Troubleshooting​

5.6.1 ClearSky Smart FleetTM CS550 Configuration​

5.6.2 Troubleshooting​

Fault Codes

Introduction​

6.1.1 Fault Code Display​

Engine Diagnostics​

Machine Fault Codes​

ClearSky CS550 Troubleshooting Procedures​

Hydraulics

General Information and Safety​

Theories of Operation​

7.2.1 Cylinders​

7.2.2 Valves​

Hydraulic Components​

Torque Values​

7.4.1 Cylinder Torque Specifications​

Electricals

General Information​

8.1.1 Applying Silicone Dielectric Compound to Electrical Connections​

8.1.2 Dielectric Grease Application​

8.1.3 Electrical Connector Examples​

Electrical Connectors​

Electrical Component Terminology​

8.3.1 General Overview​

Harness Layouts​

Board Layouts​

8.5.1 Cab Harness Fuses and Relays​

8.5.2 Power Distribution Board​

Telematics Gateway​

8.6.1 Telematics-Ready (TCU) Plug​

8.6.2 Component Locations​

8.6.3 Telematics Gateway Harness Breakdown​

Removal and Installation

Wheels​

9.1.1 Wheel and Tire Assembly​

Outrigger Assembly​

Drive Assembly​

9.3.1 Axle, Drive Shaft and Wheel Component Terminology​

9.3.2 Axle Assembly and Drive Shaft Troubleshooting​

9.3.3 Axle Serial Number​

9.3.4 Axle Specifications and Maintenance Information​

9.3.5 Axle Removal/Installation​

9.3.6 Drive Shafts​

Boom​

9.4.1 Boom Components Terminology​

9.4.2 Troubleshooting​

9.4.3 Boom System​

9.4.4 Boom Removal/Installation​

9.4.5 Manual Coupler​

9.4.6 Hydraulic Coupler​

9.4.7 Forks​

9.4.8 Boom Angle Sensor​

9.4.9 Boom Wear Pad Installation, Lubrication​

9.4.10 General Accumulator Information (Boom Ride Control)​

9.4.11 Boom Prop (If Equipped) (742, 943, 1043)​

9.4.12 Boom Prop (If Equipped) (1055, 1255)​

Cab​

9.5.1 Cab Components​

9.5.2 Serial Number Plate​

9.5.3 Cab Removal/Installation​

9.5.4 Steering Wheel​

9.5.5 Electronic Throttle Pedal​

9.5.6 Brake System​

9.5.7 Joystick Assembly​

9.5.8 Ignition Switch​

9.5.9 Dash Switches​

9.5.10 Front Wiper Assembly​

9.5.11 Rear Wiper Assembly​

9.5.12 Roof Wiper Assembly​

9.5.13 Washer Fluid Tank​

9.5.14 Heater and A/C System (if equipped)​

Engine​

9.6.1 Component Terminology​

9.6.2 Diesel Fuel​

9.6.3 Engine Serial Number​

9.6.4 Engine Replacement​

9.6.5 Engine Electrical System​

9.6.6 Surge Tank Cap​

9.6.7 Surge Tank​

9.6.8 Thermostat​

9.6.9 Engine Coolant Temperature Sensor​

9.6.10 Radiator Assembly​

9.6.11 Air Filter Assembly​

9.6.12 Alternator​

9.6.13 Starter​

9.6.14 Fuel Tank​

9.6.15 Pre-Fuel Filter and Fuel Pump​

9.6.16 Engine Exhaust System​

9.6.17 Air Conditioner (AC) Compressor (If equipped)​

9.6.18 Diesel Exhaust Fluid (DEF) Tank (if equipped for ULS)​

Transmission​

9.7.1 Component Terminology​

9.7.2 Transmission Serial Number​

9.7.3 Specifications and Maintenance Information​

9.7.4 Transmission Replacement​

9.7.5 Transmission Fluid/Filter Replacement​

9.7.6 Transmission Fluid Level Check​

9.7.7 Transmission Cooler Thermal Bypass Valve​

9.7.8 Transmission Temperature Sensor​

9.7.9 Transmission Solenoid Valves​

9.7.10 Torque Converter Diaphragm​

9.7.11 Reverse Alarm​

Hydraulic Cylinders​

9.8.1 General Cylinder Instructions​

9.8.2 Cylinder Pressure Checking​

9.8.3 Steering Cylinders​

Hydraulic Valves​

9.9.1 Steer Select Valve​

9.9.2 Main Control Valve​

9.9.3 Frame Sway Control Valve/Outrigger Valve (1043, 1055, 1255)​

9.9.4 Sway Valve (only 742, 943 without outriggers)​

9.9.5 Park Brake/Sahr Valve​

9.9.6 RAS Valve​

Implement Pump​

Electrical Components​

9.11.1 Battery​

ClearSky® LED Motion / Amber Beacon (CS550) (if equipped)​

9.12.1 ClearSky® LED Motion / Amber Beacon (CS550) (if equipped)​

Disassembly and Assembly

Drive Assembly​

10.1.1 Axle Assembly​

10.1.2 Transmission Assembly​

Boom​

10.2.1 Boom Assembly Maintenance - 742, 943, 1043​

10.2.2 Third Boom Section Removal/ Installation Only - 742, 943, 1043​

10.2.3 Boom Assembly Maintenance - 1055, 1255​

10.2.4 Fourth Boom Section Removal/Installation Only - 1055, 1255​

10.2.5 Hose Carrier Assembly - 1055, 1255​

Engine Components​

10.3.1 Engine Disassembly, Inspection and Service​

10.3.2 Fuel Tank​

DEF System​

10.4.1 DEF Tank​

Hydraulic Cylinders​

10.5.1 General Cylinder Disassembly​

10.5.2 General Cylinder Assembly Instructions​

10.5.3 Cylinder Cleaning Instructions​

10.5.4 Cylinder Inspection​

Hydraulic Valves​

10.6.1 Main Control Valve​

10.6.2 Steer Select Valve and Park Brake Valve​

10.6.3 Sway Valve (742, 943)​

10.6.4 Sway/Outrigger Valve (1043, 1055, 1255)​

10.6.5 RAS Valve​

10.6.6 Pressure Reducing Valve​

Hydraulic Components​

10.7.1 Hydraulic Oil Reservoir​

Torque/Connection Information

Hydraulic Fittings​

11.1.1 Definitions​

11.1.2 Assembly Instructions for American Standard Pipe Thread Tapered (NPTF) Connections​

11.1.3 Assembly Instructions for British Standard Pipe Thread Tapered (BSPT) Connections​

11.1.4 Assembly Instructions for 37° (JIC) Flare Fittings​

11.1.5 Assembly Instructions for 45° SAE Flare Fittings​

11.1.6 Assembly Instructions for O-Ring Face Seal (ORFS) Fittings​

11.1.7 Assembly Instructions for DIN 24° Flare Bite Type Fittings (MBTL and MBTS)​

11.1.8 Assembly Instructions for Bulkhead (BH) Fittings​

11.1.9 Assembly Instructions for O-Ring Boss (ORB) Fittings​

11.1.10 Assembly Instructions for Adjustable Port End Metric (MFF) Fittings​

11.1.11 Assembly Instructions for Metric ISO 6149 (MPP) Port Assembly Stud Ends​

11.1.12 Assembly Instructions for Adjustable Port End (BSPP) Fittings​

11.1.13 Assembly Instructions for Flange Connections (FL61 and FL62)​

11.1.14 Double Wrench Method​

11.1.15 FFWR and TFFT Methods​

11.1.16 Adjustable Stud End Assembly​

11.1.17 O-ring Installation (Replacement)​

Torque Charts​

11.2.1 SAE​

11.2.2 Metric​

Schematics

Hydraulic Schematics​

12.1.1 742​

12.1.2 943, 1043​

12.1.3 1055, 1255​

Electrical Schematics​