Why won’t my JLG 4394RT Lifting Systems shift or is slow to start?
If your JLG Lifting Systems won’t shift or is slow to start, it could be due to obstructed flow through the servo control signal lines; ensure these lines are clear and signal pressure is adequate. Also, the size and condition of the supply and drain orifices affect shift rate; verify the correct orifices are installed and not obstructed, cleaning or replacing them as necessary.
Why is there excessive noise and vibration in my JLG 4394RT Lifting Systems?
Excessive noise and vibration in JLG Lifting Systems can stem from several issues. Insufficient hydraulic fluid may cause cavitation; thus, refill the reservoir to the correct level, ensuring adequate oil supply and unobstructed lines. Trapped air can also cause cavitation, so purge all system lines and components. A loose or incorrect shaft coupling can produce vibrations; ensure the correct coupling is properly fitted. Misaligned shafts create friction, so align them correctly. Finally, overly viscous hydraulic oil can cause cavitation; replace it with fluid appropriate for operating conditions.
What to do if my JLG Lifting Systems is operating hot?
Overheating in JLG Lifting Systems can occur if there is not enough hydraulic fluid to meet cooling demands; therefore, fill the reservoir to the correct level. A faulty or obstructed heat exchanger can also cause overheating; ensure adequate airflow and good operating condition, repairing or replacing as needed. Finally, a system relief valve that is unseated or fails can lead to overheating; repair or replace any malfunctioning relief valves and verify that machine loads are not excessive.
General| Fuel Type | Diesel |
|---|---|
| Gradeability | 30 % |
| Engine Type | Diesel |
| Number of Cylinders | 4 |
| Fuel Tank Capacity | 25 gal |
| Maximum Platform Height | 43 ft |
General safety precautions for aerial platform maintenance, emphasizing attention to warnings and program adherence.
Lists key operational parameters including dimensions, workload capacity, drive speeds, and occupant limits.
Details fluid capacities for fuel tank, hydraulic tank, and engine oil.
Engine specifications for Deutz (D 2.9 L4) and GM (3.0L) models, including fuel type and oil capacity.
Specifies tire sizes, ply ratings, inflation pressures, and wheel nut torque values for various tire types.
Details the physical dimensions of the machine, including height, width, and length.
Outlines relief valve pressure settings for main, steer, and lift hydraulic circuits.
Describes the location of the machine's serial number plate and stamped serial number.
Details the function and types of sensors used, including elevation and tilt sensors.
Provides detailed specifications for lift, leveling jack, lockout, power deck, and steer cylinders.
Lists the weights of major components like platform, arm assembly, and chassis with tires.
Warns against replacing stability-critical items with parts of different specifications or weights.
Specifies recommended hydraulic oils (Mobilfluid 424, Mobil DTE 13M) and their viscosity grades.
Provides general maintenance specifications and safety tips for platform elevation and lubrication.
Tables detailing torque specifications for SAE and Metric fasteners, including different coatings.
Outlines procedures for machine preparation, inspections (pre-start, annual), and preventative maintenance schedules.
Provides general guidelines for servicing, emphasizing safety, workmanship, cleanliness, and component handling.
Details hydraulic system contamination prevention, oil recommendations, and changing procedures.
Describes procedures for measuring platform drift and cylinder drift, with acceptable limits.
Offers guidelines for inspecting and repairing pinned joints, filament wound bearings, and pins.
Details a preventive maintenance and inspection schedule, categorized by area and interval (daily, weekly, etc.).
Details maintenance and procedures for tires, wheels, drive assembly, and axle systems.
Explains the removal and installation of platform and scissor arm components.
Covers maintenance for fuel tanks, engines (Deutz, GM), and dual fuel/LPG systems.
Details the ground control station, platform control station, and joystick operations and maintenance.
Explains cylinder theory, checking procedures, repair steps, and specifications for various cylinder assemblies.
Details the theory of operation for hydraulic valves and specific circuit valves like main, flow divider, and directional.
Outlines start-up procedures and specifications for hydraulic pumps, including gear, axial, and auxiliary types.
Details procedures for charge pump filter replacement and hydraulic pressure setting adjustments.
Explains how to connect, use, and navigate the JLG handheld analyzer for system diagnostics and adjustments.
Outlines calibration procedures for elevation sensor, joystick, and tilt sensor to ensure system accuracy.
Provides a comprehensive list of fault flash codes, their communicated messages, descriptions, and priority.
Explains multimeter basics, connector handling, switch testing, and general electrical troubleshooting principles.
Refers to detailed electrical schematics for diagnosing and rectifying electrical system issues.
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