JLG Boom Lift EC660SJ Service & Maintenance Manual 3122551800 2026

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JLG Boom Lift EC660SJ Service & Maintenance Manual 3122551800 2026
Size: 56.08 MB
Format: PDF
Language: English
Brand: JLG
Type of Machine: Boom Lift
Type of Manual: Service & Maintenance Manual, Electrical and Hydraulic Diagrams
Model: JLG EC660SJ Boom Lift
Part Number: 3122551800
Publication Date: 2026
Number of Pages: 684 Pages

Contents:
Safety

General​

1.1.1 Disclaimer​

1.1.2 Operation & Safety Manual​

Safety Information​

1.2.1 Safety Alert System and Signal Words​

Safety Hazards​

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 Machine Specifications​

2.1.2 Machine Dimensional Data​

2.1.3 Electrical Data​

2.1.4 Battery Monitoring Specifications​

2.1.5 Tires​

2.1.6 Critical Stability Weights​

2.1.7 Torque Requirements​

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 Schedule​

Machine Characteristics​

2.5.1 Ground Control Keyswitch System​

2.5.2 Platform Control Enable System​

2.5.3 Drive System​

2.5.4 Drive Orientation System​

2.5.5 Function Speed Control System​

2.5.6 Oscillating Axle System​

2.5.7 Electronic Platform Leveling​

2.5.8 Chassis Tilt Indicator System​

2.5.9 Platform Load Sensing System (LSS)​

2.5.10 Auxiliary Power System​

2.5.11 Tires and Counterweight​

2.5.12 Platform​

2.5.13 Wire Rope Break Indicator​

2.5.14 Transport Position Sensing System​

2.5.15 Beyond Transport - Drive Speed Cutback System​

2.5.16 Drive/Steer – Boom Function Interlock System​

2.5.17 Dual Capacity System​

2.5.18 Ground Panel Display​

Maintenance and Inspection Schedules

Machine Preparation, Inspection, and Maintenance​

3.1.1 General​

3.1.2 Preparation, Inspection, and Maintenance​

3.1.3 Pre-Start Inspection​

3.1.4 Pre-Delivery Inspection and Frequent Inspection​

3.1.5 Annual Machine Inspection​

3.1.6 Preventive Maintenance​

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 Reassembly​

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 Inspection Schedules​

3.3.2 Maintenance Schedules​

Pins and Composite Bearing Repair Guidelines​

Tires and Wheels​

3.5.1 Tire Inflation​

3.5.2 Tire Damage​

Boom Inspection and Maintenance​

3.6.1 Wire Rope Tensioning Procedure​

3.6.2 Wire Rope​

3.6.3 Boom Cleanliness Guidelines​

3.6.4 Boom Wear Pad Inspection​

Hydraulic Filter Replacement​

3.7.1 Hydraulic Filter Removal​

3.7.2 Hydraulic Filter Installation​

Turntable Bearing Inspection​

3.8.1 Turntable Bearing Mounting Bolt Condition Check​

3.8.2 Wear Tolerance​

Battery Packs​

3.9.1 Battery Monitoring System​

3.9.2 Troubleshooting Battery Packs​

Battery Maintenance​

3.10.1 Battery Maintenance (Daily)​

3.10.2 Battery Maintenance (Quarterly)​

3.10.3 Battery Additional Maintenance Recommendations​

3.10.4 Battery Charging - On Board Charger​

3.10.5 Over-Charging/High Battery Temperature​

Battery Charger​

3.11.1 General Information​

3.11.2 Battery Charging System Components​

3.11.3 AC Cable​

3.11.4 Battery Charger User Interface​

3.11.5 LED Indicators​

3.11.6 Operating Instructions​

3.11.7 Battery Charger Alarm Visualization​

3.11.8 Maintenance Instructions​

Electric Motor​

Auxiliary Power System​

Testing, Calibrations and Special Procedures

Special Tools​

4.1.1 Multimeter Basics​

4.1.2 Threadlocking Compound​

4.1.3 Tools Catalog​

SkyGuard​

4.2.1 Operation​

4.2.2 Function Test​

4.2.3 Diagnostics and Troubleshooting​

4.2.4 Fault Codes​

Load Sensing System​

4.3.1 Preparation​

4.3.2 Testing LSS Control System Warnings and Interlocks​

4.3.3 Testing LSS Control System Capacity Indication​

4.3.4 Testing LSS Platform Load Reading with Calibrated Weights​

4.3.5 Testing LSS Platform Load Reading with a Known Weight​

Performing Machine Tests​

4.4.1 Test from the Platform​

4.4.2 Test from the Ground Station​

Calibration Preparation​

4.5.1 JLG Analyzer​

4.5.2 Calibration Preparation​

Load Sensing System Calibration​

Tilt Sensor Calibration​

Boom Angle Calibration​

Level Up Crackpoint Calibration​

Level Down Crackpoint Calibration​

Platform Angle Sensor Calibration​

Steer Calibration​

Special Procedures​

4.13.1 Emergency Boom Lowering Procedure​

4.13.2 Drive Cutout Override Service Mode​

4.13.3 Cylinder Checking Procedure​

4.13.4 Cylinder Drift​

4.13.5 Hydraulic Circuits​

4.13.6 Hydraulic Pressure Settings and Adjustments​

4.13.7 Hydraulic Pressures​

4.13.8 Oscillating Axle Bleeding Procedure and Lockout Test​

Wheel Drive Hub​

Swing Drive​

System Software

Load Sensing System (LSS)​

5.1.1 Theory of Operation​

5.1.2 Load Sensing Gauge Removal/ Installation​

JLG Analyzer​

5.2.1 Machine Data Access​

5.2.2 Hand Held Analyzer​

5.2.3 Mobile Analyzer​

5.2.4 Analyzer Software Versions P2.29​

Analyzer Software Accessibility​

5.3.1 Access Level​

5.3.2 Diagnostic​

5.3.3 Machine Set-Up​

Machine Configuration Programming Settings​

Personalities​

5.5.1 Machine Personality Settings and Function Speed​

Function Test​

CANBUS Communications​

Service Mode​

5.8.1 Load Sensing System​

5.8.2 Drive Cutout Override​

Fault Codes

Fault Codes Introduction​

Machine Fault Codes​

6.2.1 General​

6.2.2 LSS Troubleshooting​

6.2.3 System Test Messages​

Machine Diagnostics Parameters​

Hydraulics

General Information and Safety​

Theories of Operation​

7.2.1 Cylinders​

7.2.2 Valves​

Hydraulic Components​

7.3.1 Hydraulic Oil Tank​

7.3.2 Hydraulic Pump Pre-Fill Procedure​

7.3.3 Main Control Valve Pressure Setting​

7.3.4 Platform Control Valve Pressure Setting Procedure​

Torque Values​

7.4.1 Cylinder Torque Specifications​

7.4.2 Valve Torque Specifications​

Standard Hydraulic Diagram - Boom And Turntable​

7.5.1 2WS​

7.5.2 4WS​

Hydraulic Diagram - Chassis​

7.6.1 4WD 2WS​

7.6.2 4WD 4WS​

Electricals

General Information​

8.1.1 Applying Silicone Dielectric Compound to Electrical Connections​

8.1.2 Dielectric Grease Application​

Electrical Connectors​

8.2.1 Deutsch Connectors​

Electrical Component Terminology​

Harness Layouts​

Board Layouts​

8.5.1 Ground Control Module Pin Connections​

8.5.2 Platform Control Module Pin Connections​

Wiring Harness and Connector Label Diagrams​

8.6.1 Connector Labels​

8.6.2 Component Labels​

Telematics Gateway​

8.7.1 Telematics-Ready (TCU) Plug​

Removal and Installation

Wheel and Tire​

Chassis/Frame Assembly​

9.2.1 Axle and Drive Assemblies Troubleshooting​

9.2.2 Front and Rear Axle Assembly​

9.2.3 Drive Hub and Motor​

9.2.4 Knuckle Assembly​

Boom​

9.3.1 Boom Components Terminology​

9.3.2 Troubleshooting​

9.3.3 Main Boom Powertrack​

9.3.4 Main Boom Assembly​

9.3.5 Boom Sensors​

9.3.6 Jib and Rotator Assembly​

Platform​

9.4.1 Platform Support​

9.4.2 Bolt-On External Fall Arrest​

Electric Motor​

9.5.1 Removal​

9.5.2 Installation​

Transmission​

Hydraulic Cylinders​

9.7.1 Main Boom Lift Cylinder​

9.7.2 Platform Level Cylinder​

9.7.3 Steer Cylinder​

9.7.4 Jib Lift Cylinder​

9.7.5 Axle Lockout Cylinder​

Hydraulic Valves​

9.8.1 Platform Valve​

9.8.2 Main Control Valve​

9.8.3 Traction Control Valve​

9.8.4 Axle Valve​

Hydraulic Pumps​

9.9.1 Drive Pump​

9.9.2 Function Pump​

Electrical Components​

9.10.1 Battery (Electric Motor Side)​

9.10.2 Battery Pack (Hydraulic Tank Side)​

Turntable​

9.11.1 Swing Drive​

9.11.2 Rotary Coupling​

9.11.3 Swing Bearing​

9.11.4 Counterweight​

Disassembly and Assembly

Drive Assembly​

10.1.1 Drive Hub​

10.1.2 Drive Motor​

Boom and Jib Assembly​

10.2.1 Main Boom Assembly​

10.2.2 Rotator Assembly​

Platform​

Pumps​

10.4.1 Function Pump​

10.4.2 Drive Pump​

Main Lift Cylinder​

Platform Level Cylinder​

Jib Lift Cylinder​

Steer Cylinder​

Telescope Cylinder​

Axle Lockout Cylinder​

Hydraulic Valves​

Hydraulic Components​

10.12.1 Hydraulic Oil Tank​

Turntable​

10.13.1 Swing Motor​

10.13.2 Rotary Coupling​

10.13.3 Rotary Coupling Seal Kit​

Powertrack​

10.14.1 Remove Link​

10.14.2 Install New Link​

10.14.3 Replace Fixed End Brackets​

10.14.4 Replace Moving End Brackets​

Torque/Connection Information

Hydraulic Fittings​

11.1.1 Tapered Thread Types​

11.1.2 Straight Thread Types, Tube and Hose Connections​

11.1.3 Straight Thread Types, Port Connections​

11.1.4 Flange Connection Types​

11.1.5 Tightening Methods​

11.1.6 Assembly and Torque Specifications​

11.1.7 General Tube Type Fitting Assembly Instructions​

11.1.8 Assembly Instructions for American Standard Pipe Thread Tapered Connections.​

11.1.9 Assembly Instructions for British Standard Pipe Thread Tapered Connections​

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

11.1.11 Assembly Instructions for 45° SAE Flare Fittings​

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

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

11.1.14 Assembly Instructions for Bulkhead (BH) Fittings​

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

11.1.16 Assembly Instructions for Adjustable Port End Metric Fittings​

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

11.1.18 Assembly instructions for Adjustable Port End (BSPP) Fittings​

11.1.19 Assembly Instructions for Flange Connections: (FL61 and FL62)​

11.1.20 Double Wrench Method​

11.1.21 FFWR and TFFT Methods​

11.1.22 Adjustable Stud End Assembly​

11.1.23 O-ring Installation (Replacement)​

Torque Charts​

11.2.1 SAE Fastener Torque Chart​

11.2.2 Metric Fastener Torque Chart​

Schematics

Hydraulic Schematics​

Electrical Schematics​