JLG Boom Lift 800AJ Service & Maintenance Manual 3122561900 2026

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JLG Boom Lift 800AJ Service & Maintenance Manual 3122561900 2026
Size: 87.85 MB
Format: PDF
Language: English
Brand: JLG
Type of Machine: Boom Lift
Type of Manual: Service & Maintenance Manual, Electrical and Hydraulic Diagrams
Model: JLG 800AJ Boom Lift
Part Number: 3122561900
Publication Date: 2026
Number of Pages: 948 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 Engine Data​

2.1.4 Tires​

2.1.5 Critical Stability Weights​

2.1.6 Torque Requirements​

2.1.7 Component Data​

2.1.8 Major Component Weights​

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 Cold Start System (Diesel)​

2.5.4 Fuel level Cutout System​

2.5.5 HRC Engine Emission Characteristics​

2.5.6 Diesel Particulate Filter (If Equipped)​

2.5.7 Drive System​

2.5.8 Drive Orientation System​

2.5.9 Function Speed Control System​

2.5.10 Oscillating Axle System​

2.5.11 Main Lift End Stroke Dampening System​

2.5.12 Chassis Tilt Indicator System​

2.5.13 Platform Load Sensing System (LSS)​

2.5.14 ClearSky™ System Ready​

2.5.15 Tires and Counterweight​

2.5.16 Platform​

2.5.17 QuikStick Lift System​

2.5.18 Auxiliary Power System​

2.5.19 Transport Position Sensing System​

2.5.20 Beyond Transport - Drive Speed Cutback System​

2.5.21 Drive Steer Boom Function​

2.5.22 Tower Boom Sequence Valve System​

2.5.23 Ground Panel Display​

2.5.24 Upright Level System​

2.5.25 Dual Fuel System​

2.5.26 Counterweight​

Clearsky Smart Fleet (If Equipped)​

2.6.1 General​

2.6.2 ClearSky Smart Fleet™ — Access Control​

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 Daily​

3.3.2 First 50 Hours​

3.3.3 Every 150 Hours or 3 Months​

3.3.4 First 300 Hours or 6 Months​

3.3.5 Every 600 Hours or 1 Year​

3.3.6 Every 1000 Hours or 1 Year​

3.3.7 Every 1200 Hours or 2 Years​

Pins and Composite Bearing Repair Guidelines​

Tires and Wheels​

3.5.1 Tire Inflation​

3.5.2 Tire Damage​

Fuel Tank Inspection​

Boom Inspection and Maintenance​

3.7.1 Boom Cleanliness Guidelines​

3.7.2 Boom Wear Pad Inspection​

Hydraulic Filter Replacement​

3.8.1 Removal​

3.8.2 Installation​

Turntable Bearing Inspection​

3.9.1 Turntable Bearing Mounting Bolt Condition Check​

3.9.2 Wear Tolerance​

Engine General Inspection​

3.10.1 General Maintenance​

3.10.2 Glow Plugs​

3.10.3 Replacing Engine Oil​

3.10.4 Replacing the Oil Filter​

3.10.5 Replacing the Primary Fuel Filters​

3.10.6 Replacing the Fuel Pre-Filter​

3.10.7 Replacing the Auxiliary Fuel Filter For Deutz D2011LO40 (T4I) (Only)​

3.10.8 Spark Arrester Cleaning Instructions For Deutz D2011LO40 (T4I) (Only)​

3.10.9 Replacing the Fuel Strainer For Deutz D2011LO40 (T4I) (Only)​

Bio Fuel In Deutz Engines​

3.11.1 General​

3.11.2 Bio Fuel​

3.11.3 Biological Contamination In Fuels​

Deutz EMR2​

Deutz EMR4​

Deutz EMR5​

Generator Inspection​

3.15.1 2500W Generator​

3.15.2 4000W Generator​

3.15.3 7500W Generator​

Testing, Calibrations and Special Procedures

Special Tools​

4.1.1 Multimeter Basics​

4.1.2 Threadlocking Compound​

4.1.3 Tools Catalog​

Testing Procedures​

4.2.1 Starter​

4.2.2 SkyGuard​

4.2.3 LSS Testing and Evaluation​

4.2.4 Test from the Platform​

4.2.5 Test from the Ground Station​

Calibration Procedures​

4.3.1 JLG Analyzer​

4.3.2 Calibration Preparation​

4.3.3 Load Sensing System Calibration​

4.3.4 Calibrating Tilt Sensor​

Special Procedures​

4.4.1 Fuel Tank Cleaning and Drying​

4.4.2 Cylinder Checking Procedure​

4.4.3 Cylinder Drift​

4.4.4 Hydraulic Circuits​

4.4.5 Hydraulic Pressure Settings and Adjustments​

4.4.6 Hydraulic Pressures​

4.4.7 Oscillating Axle Bleeding Procedure​

4.4.8 Oscillating Axle Lockout Test​

4.4.9 Engine Operating States​

4.4.10 Engine Start Conditions​

4.4.11 Engine RPM Levels​

4.4.12 Engine Controls​

4.4.13 Engine Startup Procedure (Kubota)​

4.4.14 Oil Sampling​

4.4.15 Control System Startup Checks​

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 Flow Chart​

Analyzer Software Accessibility​

5.3.1 Access Level​

5.3.2 Diagnostic​

5.3.3 Machine Set-Up​

5.3.4 Personalities​

5.3.5 Operator Tools​

5.3.6 Calibrations​

Function Test​

CANBUS Communications​

Service Mode​

5.6.1 Load Sensing System​

Upright Monitoring System (UMS)​

5.7.1 Re-Synchronizing Upright​

5.7.2 Calibration​

5.7.3 Calibration Faults​

5.7.4 Function Check​

5.7.5 Service Mode/Tower Boom Retrieval​

ClearSky (CS550) Configuration and Troubleshooting​

5.8.1 ClearSky Smart FleetTM CS550 Configuration​

5.8.2 Troubleshooting​

Fault Codes

Fault Codes Introduction​

Engine Diagnostic​

6.2.1 Deutz D2011LO40 Engine​

6.2.2 Deutz TD2.9L4 (Stage V)/TD2.9L4 China IV Engine​

6.2.3 Deutz TD2.9L4 (T4F) Engine​

6.2.4 Ford MSG425-DF Engine​

6.2.5 Cross Reference Chart​

6.2.6 Engine Fault Codes​

Machine Fault Codes​

6.3.1 General​

6.3.2 LSS Troubleshooting​

6.3.3 System Test Messages​

6.3.4 ClearSky Smart Fleet DTC Fault Codes​

ClearSky CS550 Troubleshooting Procedures​

Machine Diagnostics Parameters​

Deutz EMR Fault Codes​

6.6.1 EMR2 Fault Codes​

6.6.2 EMR4 Fault Codes​

6.6.3 EMR5 Fault Codes​

UMS Troubleshooting and Diagnostic Trouble Codes (DTC)​

6.7.1 Backward Stability Concern DTC (2532)​

6.7.2 Forward Stability Concern DTC (2530)​

6.7.3 Out of Usable Range DTC (2531)​

6.7.4 UMS Sensor Not Calibrated DTC (816)​

6.7.5 UMS Sensor Faulted DTC (817)​

6.7.6 Calibration Faults​

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 Component Start-Up Procedures And Recommendations​

7.3.3 Hydraulic Pump Pre-Fill Procedures – Ford Engine​

7.3.4 Hydraulic Drive Pump Pre-Fill Procedures – Deutz Engine​

7.3.5 Function Pump Pressure Setting Procedure​

7.3.6 Main Control Valve Pressure Setting Procedure​

7.3.7 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​

Hydraulic Diagram - Chassis​

7.6.1 2WD 2WS – Ford Engine​

7.6.2 4WD 2WS – Ford Engine​

7.6.3 4WD 4WS – Ford Engine​

7.6.4 2WD 2WS – Deutz Engine​

7.6.5 4WD 2WS – Deutz Engine​

7.6.6 4WD 4WS – Deutz Engine​

7.6.7 2WD 2WS – Deutz Engine (with tow bar)​

7.6.8 4WD 2WS – Deutz Engine (with tow bar)​

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​

8.4.1 Turntable — 1 of 2​

8.4.2 Turntable — 2 of 2​

8.4.3 Engine Deutz D2011​

8.4.4 Engine Deutz 2.9L4​

8.4.5 Engine Ford DF​

8.4.6 Boom​

8.4.7 Platform​

8.4.8 Controls​

Board Layouts​

8.5.1 Ground Control Module Pin Connections​

8.5.2 Platform Control Module Pin Connections​

AMP Connector​

8.6.1 Applying Silicone Dielectric Compound to AMP Connectors​

8.6.2 Assembly​

8.6.3 Disassembly​

8.6.4 Wedge Lock​

8.6.5 Service - Voltage Reading​

Wiring Harness and Connector Label Diagrams​

8.7.1 Connector Labels​

8.7.2 Component Labels​

Telematics Gateway​

8.8.1 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 Spindle 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 Upright​

9.3.6 Tower Boom Assembly​

9.3.7 Dual Axis Sensor​

9.3.8 Jib and Rotator Assembly​

Platform​

9.4.1 Platform Control Valve​

9.4.2 Platform (Rapid Replaceable Platform)​

9.4.3 Platform Support (Traditional Design)​

9.4.4 Platform Support (Rapid Replaceable Platform)​

9.4.5 Bolt-On External Fall Arrest​

Engine​

9.5.1 Component Terminology​

9.5.2 Engine Serial Number​

9.5.3 Engine Replacement​

9.5.4 Surge Tank (Deutz TD2.9L4 (T4F)/TD2.9L4 (Stage V)/TD2.9L4 China IV)​

9.5.5 Pump Coupling Kit​

9.5.6 Air Filter Assembly​

9.5.7 Radiator Assembly​

9.5.8 Thermostat​

9.5.9 Coolant Temperature Sensor​

9.5.10 Relay Assembly​

9.5.11 Starter​

9.5.12 Alternator​

9.5.13 Fuel Tank​

9.5.14 Pre-Fuel Filter and Fuel Pump​

Transmission​

Hydraulic Cylinders​

9.7.1 Main Boom Lift Cylinder​

9.7.2 Main Boom Telescope Cylinder​

9.7.3 Upright Level Cylinder​

9.7.4 Tower Boom Lift Cylinder​

9.7.5 Tower Telescope Cylinder​

9.7.6 Master Cylinder​

9.7.7 Platform Level Cylinder​

9.7.8 Articulating Jib and Jib Lift Cylinder​

9.7.9 Steer Cylinder​

9.7.10 Axle Lockout Cylinder​

Hydraulic Valves​

9.8.1 Platform Control Valve​

9.8.2 Main Control Valve​

9.8.3 Brake/2 Speed Valve​

Hydraulic Pumps​

9.9.1 Variable Pump Assembly​

9.9.2 Hydrostatic Pump Assembly​

Electrical Components​

9.10.1 Battery​

Turntable​

9.11.1 Swing Drive​

9.11.2 Swing Bearing​

Generator and Pulley​

9.12.1 For 7500W and 4000W Generator - Deutz TD2.9L4​

9.12.2 For 2500W Generator - Ford MSG425-DF​

9.12.3 For 2500W Generator - Deutz D20110L40​

9.12.4 For 7500W Skypower Generator - Deutz D20110L40​

9.12.5 For 7500W Skypower Generator - Ford MSG425-DF​

9.12.6 For 4000W Generator - Deutz D20110L40​

9.12.7 For 2500W Generator - Kubota WG2503 and Deutz T4F​

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

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

Disassembly and Assembly

Drive Assembly​

10.1.1 Drive Hub (Torque)​

10.1.2 Drive Brake​

10.1.3 Drive Motor​

Boom and Jib Assembly​

10.2.1 Main Boom Disassembly/Assembly​

10.2.2 Tower Boom Disassembly/Assembly​

10.2.3 Rotator Disassembly/Assembly​

Platform​

Engine Components​

10.4.1 Engine Disassembly, Inspection and Service​

10.4.2 Fuel Tank​

Pumps​

10.5.1 Function Pump​

10.5.2 Servo Controlled Piston Pump​

10.5.3 Charge Pump Adapter Assembly​

10.5.4 Manual Servo Control Basic Assembly​

10.5.5 Manual Servo Control Assembly Options​

10.5.6 Rotating Kit Assembly​

Hydraulic Cylinders​

10.6.1 Axle Lockout Cylinder​

10.6.2 Platform Level Cylinder​

10.6.3 Main Boom Lift, Tower Lift and Upright Level Cylinder​

10.6.4 Jib Lift Cylinder​

10.6.5 Master Cylinder​

10.6.6 Steer Cylinder​

10.6.7 Main Boom Telescope Cylinder​

10.6.8 Tower Boom Telescope Cylinder​

Hydraulic Valves​

Hydraulic Components​

10.8.1 Hydraulic Oil Tank​

Turntable​

10.9.1 Swing Motor​

10.9.2 Rotary Coupling Seal Kit​

Generator Disassembly and Assembly​

10.10.1 Disassembly​

10.10.2 Assembly​

Powertrack Maintenance (task)​

10.11.1 Flat Bar Removal​

10.11.2 Round Bar/Poly Bar Removal​

10.11.3 Removing and Installing Links​

10.11.4 Installing a New Flat Bar​

10.11.5 Installing a New Round Bar/Poly Roller​

10.11.6 Replacing a Fixed End Bracket​

10.11.7 Replacing a Moving End Bracket​

10.11.8 Replacing a One Piece Bracket​

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​

Deutz EMR2 Schematics​

12.3.1 Vehicle Side Connection Diagram​

12.3.2 Engine Side Connection Diagram - Sheet 1 of 2​

12.3.3 Engine Side Connection Diagram - Sheet 2 of 2​

12.3.4 Engine Plug Pin​

12.3.5 Vehicle Plug Pin Identification​

Deutz EMR4 Schematics​

12.4.1 Power Harness​

12.4.2 Equipment Harness​

12.4.3 D2.1 Engine Plug Pin Assignment​

12.4.4 D2.2 Unit Plug Pin Assignment​

Deutz EMR5 Schematics​

12.5.1 Power Harness​

12.5.2 Exhaust After Treatment Harness​

12.5.3 Equipment Harness - Sheet 1 of 5​

12.5.4 Equipment Harness - Sheet 2 of 5​

12.5.5 Equipment Harness - Sheet 3 of 5​

12.5.6 Equipment Harness - Sheet 4 of 5​

12.5.7 Equipment Harness - Sheet 5 of 5​

12.5.8 Engine Plug Pin Identification​

12.5.9 Vehicle Plug Pin Identification​

4000W Generator Schematic​

12.6.1 Generator and Controller Circuit Diagram​

12.6.2 Lead Connection List​

7500W Generator Schematic​

12.7.1 Troubleshooting Circuit Diagram​

12.7.2 Generator and Controller Circuit Diagram​

12.7.3 Power Board PC1 Circuit Diagram​

12.7.4 Power Board PC2 Electrical Circuit Diagram​

12.7.5 Lead Connection List​