JLG 1250AJP Aerial Platform Service and Maintenance Manual – 3121171 Rev S PDF Download

Description

JLG 1250AJP Service and Maintenance Manual – 3121171 Rev S

This is the complete JLG 1250AJP Service and Maintenance Manual, published under document number 3121171 Revision S. It is the comprehensive workshop reference for the 1250AJP aerial work platform, covering every major system on the machine from the chassis and turntable through the tower and main boom to the platform and its electronic controls. Whether you are performing routine maintenance, diagnosing a fault code, rebuilding a hydraulic cylinder, or calibrating the JLG Control System, this manual provides the procedures, specifications, and diagrams needed to complete the job correctly.

File Details

• Manual Type: Service and Maintenance Manual
• Brand: JLG
• Model: 1250AJP
• Document Number: 3121171
• Revision: S (May 31, 2019)
• Language: English
• Page Count: 788
• File Format: PDF

Chapters Covered

• Section A – Introduction: Maintenance safety precautions, hydraulic system safety, general maintenance warnings
• Section 1 – Specifications: Operating specifications and performance data, capacities, chassis specifications, tires, dimensional data, engine data (Caterpillar 3.4T, Deutz BF4M2011, Deutz TD2011L4, Deutz TCD2.9L4), torque requirements, major component weights, pressure settings, hydraulic oil specifications, lubrication and operator maintenance
• Section 2 – General: Machine preparation, inspection and maintenance, pre-start inspection, pre-delivery and frequent inspection, annual machine inspection, preventative maintenance, service and guidelines, cleanliness, component removal and installation, disassembly and reassembly, pressure-fit parts, bearings, gaskets, bolt usage and torque application, hydraulic lines and electrical wiring, lubrication and information, cylinder drift test, pins and composite bearing repair guidelines, welding on JLG equipment
• Section 3 – Chassis & Turntable: Tires and wheels, axle extension system, axle limit switch adjustment, drive system, steering control system, drive/steering speed control, traction control system, drive orientation system, ground control enable system, oscillating axle system, oscillating axle bleeding and lockout test, wheel drive assembly, drive hub (Rexroth, Bonfiglioli, Reggiana Riduttori), swing drive hub, swing drive, swing brake, swing motor, gear backlash procedure, swing drive lubrication, turntable bearing, swing speed proportioning, chassis tilt indicator system, rotary coupling, generator, cold weather package, engine (glow plugs, oil level, oil change, filters), Deutz EMR 2, bio fuel, Deutz turbocharger operation, CAT DGC diagnostic support and trouble code definitions, auxiliary power system, counterweight
• Section 4 – Boom & Platform: Platform control enable system, transport position sensing system, beyond transport drive speed cutback, drive/steer boom function interlock (CE only), jib stow system, envelope control system, tower path control system, automatic main boom control system, electrical retrieval system, hydraulic retrieval system, controlled boom angle system, slow down system, dual capacity system, hydraulic system warm up, reduced platform heights, electronic platform leveling, platform support removal/installation, rotator removal/installation, main boom disassembly/assembly, tower boom installation and assembly, pin clamp installation, main boom transport angle switch, tower transport length switch, main boom transport length switches, dual capacity switches, tower telescope cylinder removal/installation, tower lift cylinder removal/installation, main lift cylinder removal/installation, main boom telescope cylinder removal/installation, powertrack maintenance, hose routing procedure, tower boom drift test, rotary actuator, bolt-on external fall arrest, SkyGuard
• Section 5 – Hydraulics and Hydraulic Schematics: Lubricating O-rings in the hydraulic system, hydraulic connection assembly and torque specification, cylinder repair (disassembly, cleaning, inspection, assembly), counterbalance valve check, hydraulic tank, hydraulic return filter, enable valves, pressure setting procedure, drive pumps, function pump, drive and function pump start up, hydraulic schematics (8 sheets)
• Section 6 – JLG Control System: Introduction, analyzer connection and use, changing access level, adjusting parameters, machine setup, machine personality settings and function speeds, machine orientation when setting speeds, CANbus communications, calibration instructions, system test, calibrating steer, calibrating drive, calibrating boom valves, LSS system, resetting the MSSO system, electronic platform leveling, calibrating platform level, calibrating tilt sensor, boom sensor calibration, boom control system violation, CANbus troubleshooting, load moment pin troubleshooting, diagnostic trouble code chart
• Section 7 – Basic Electrical Information & Electrical Schematics: General, multimeter basics, applying silicone dielectric compound to electrical connections, dielectric grease application, AMP connector, Deutsch connectors, telematics gateway, electrical schematics (21 sheets), wiring harness installation

IMAGES PREVIEW

This JLG 1250AJP service manual is the factory workshop reference used by professional technicians to service and repair the 1250AJP aerial platform. The manual opens with critical safety precautions that must be observed during any maintenance task, then moves into complete specifications for the machine including operating data, capacities, dimensional data, engine data for all equipped engine variants, torque requirements, component weights, and pressure settings. The hydraulic oil specifications section covers viscosity grades for different operating temperature ranges, including Mobil DTE 10 Excel 32, UCon Hydrolube HP-5046, Mobil EAL H 46, Mobil EAL 46, Quintolubric 888-46, Mobilfluid 424, and Exxon Univis HVI 26. A detailed lubrication and operator maintenance section with diagrams identifies every grease point, filter, and fluid check on the machine.

The chassis and turntable section provides procedures for the axle extension system, steering control system (conventional two-wheel, crab, and coordinated modes), traction control, drive orientation, oscillating axle bleeding and lockout testing, wheel drive assembly removal and installation, and complete disassembly and assembly procedures for all three drive hub variants: Rexroth, Bonfiglioli, and Reggiana Riduttori. The swing drive section includes roll and leak testing, motor control valve disassembly, motor and brake disassembly, hub-shaft disassembly, carrier disassembly, and complete assembly procedures with exploded view diagrams. The turntable bearing section covers mounting bolt condition checks, bearing wear measurement, bearing removal and installation, and torque sequences.

The engine section covers the Caterpillar 3.4T, Deutz BF4M2011, Deutz TD2011L4, and Deutz TCD2.9L4 diesel engines with specifications, glow plug operation, oil level checking, oil and filter changes, fuel filter replacement, and fuel strainer cleaning. The Deutz EMR 2 engine management system section provides connector pin identifications, fault codes, and troubleshooting. The CAT DGC diagnostic support section provides detailed diagnostic trouble code definitions with troubleshooting flow charts for the CAT 3.4 engine ECM.

The boom and platform section is extensive, covering the platform control enable system, transport position sensing system, envelope control system, tower path control, automatic main boom control, electrical and hydraulic retrieval systems, controlled boom angle system, slow down system, dual capacity system, hydraulic warm up, reduced platform heights, and electronic platform leveling. Complete removal and installation procedures are provided for the platform support, rotator, main boom, tower boom, tower telescope cylinder, tower lift cylinder, main lift cylinder, and main boom telescope cylinder. The pin clamp installation procedure, powertrack maintenance, hose routing, tower boom drift test, rotary actuator rebuild, bolt-on external fall arrest, and SkyGuard operation and diagnostics are all covered with detailed instructions and illustrations.

The hydraulics section begins with O-ring lubrication procedures, then provides complete hydraulic connection assembly and torque specifications for NPTF, BSPT, JIC, SAE, ORFS, MBTL, MBTS, BH, ORB, MPP, MFF, BSPP, and flange connections. Cylinder repair procedures cover disassembly, cleaning, inspection, and assembly with torque specifications for cylinder heads and tapered bushings. The pressure setting procedure covers the function pump, main valve bank, frame valve bank, and platform valve bank with specific pressure values for swing, main telescope, axle extend/retract, steer left/right, platform level up/down, and jib up/down. Drive pump troubleshooting, charge pressure relief valve adjustment, mechanical centering, hydraulic centering, high pressure relief valve adjustment, and charge pump removal and inspection are all detailed. The function pump section covers sealing the drive shaft, complete unit disassembly and assembly, adjustments, tightening torques, and pump control disassembly for cleaning. Eight hydraulic schematic sheets provide the complete hydraulic circuit diagrams.

The JLG Control System section is the electronic brain of the machine, and this manual provides complete coverage of the analyzer, machine setup, personality settings, function speeds, CANbus communications, and calibration procedures. The calibration instructions cover steering, drive, boom valves, platform level crack points, tilt sensor, and the complete boom sensor calibration procedure with all positions. The system test function is described for both platform and ground station testing. The LSS (Load Sensing System) section covers the diagnostic menu, calibration procedure, testing and evaluation, and troubleshooting. The MSSO reset procedure, electronic platform leveling fault warnings and responses, CAN errors, platform level and jib valve operation, platform level calibration, tilt sensor calibration, and boom sensor calibration are all covered in detail. The diagnostic trouble code chart provides a comprehensive list of fault codes with descriptions and checks.

The electrical section covers multimeter basics including grounding, backprobing, min/max, polarity, scale, voltage measurement, resistance measurement, continuity measurement, and current measurement. The section on applying silicone dielectric compound to electrical connections explains where to apply and where not to apply dielectric grease. AMP connector and Deutsch connector assembly and disassembly procedures are provided with detailed illustrations. The telematics gateway section provides the TCU plug pinout and describes the data available through the telematics device. Twenty-one electrical schematic sheets provide the complete electrical circuit diagrams, and wiring harness installation sheets show the physical routing of harnesses throughout the machine.

What This Manual Enables You to Do

With this JLG 1250AJP service and maintenance manual, you can perform every scheduled maintenance task, diagnose and repair hydraulic and electrical faults, rebuild cylinders and drive hubs, calibrate the JLG Control System, and service the engine and drivetrain. The manual provides the exact torque values, pressure settings, clearances, and adjustment procedures that JLG specifies, ensuring that repairs are done correctly and safely. The hydraulic schematics and electrical schematics allow you to trace circuits and understand how systems interact. The diagnostic trouble code charts help you quickly identify fault conditions and determine the correct corrective action. The calibration procedures ensure that after repairs or component replacement, the machine’s control system is properly calibrated for safe operation.

This manual is essential for any technician responsible for maintaining a JLG 1250AJP. Without the correct specifications and procedures, there is a risk of improper repair, machine damage, or unsafe operation. The detailed illustrations, exploded views, and step-by-step instructions remove the guesswork from maintenance and repair.

Delivered as an instant PDF download, this manual can be saved to your computer, tablet, or smartphone and printed as needed. There is no shipping delay and no physical book to wait for. You can search the document, zoom in on diagrams, and print only the pages you need for the job at hand.