Moving a Non-Operational JLG Boom Lift Safe Procedures and Hydraulic Precautions

[MikePhua]

The JLG Boom Lift and Its Transport Challenges
JLG Industries, founded in 1969, is a global leader in aerial work platforms and telehandlers. Their boom lifts—especially the 600 and 800 series—are widely used in construction, maintenance, and industrial access. These machines feature telescoping or articulating booms, hydraulic drive systems, and electronic control modules. When operational, they can be driven and steered with precision. But when inoperative due to electrical failure, engine issues, or hydraulic faults, moving them becomes a logistical and mechanical challenge.
A non-running boom lift cannot be simply towed like a trailer. Its drive motors are hydraulic, and without active pressure, the system locks. Attempting to drag or push the unit without proper preparation risks damaging the drive hubs, hydraulic seals, and internal components.
Terminology Annotation

• Drive Hub: The assembly that transmits hydraulic power to the wheels, often containing planetary gears and brake mechanisms.
  
• Tow Valve: A manual bypass valve that allows hydraulic fluid to circulate freely, enabling the wheels to turn without active pressure.
  
• Hydraulic Lock: A condition where fluid trapped in the motor prevents movement, acting like a brake.
  
• Articulating Boom: A lift arm with multiple joints, allowing complex movement paths.
  

Identifying the Tow Valve and Preparing for Movement
Most JLG boom lifts are equipped with tow valves located near the drive motors or inside the wheel wells. These valves must be manually opened to allow fluid bypass. The process typically involves:

• Locating the valve using the service manual or schematic
  
• Using a wrench or hex key to rotate the valve counterclockwise
  
• Confirming that the valve is fully open before attempting movement
  
• Repeating the process for each drive motor
  

Some models use a centralized hydraulic manifold with labeled bypass ports. In others, the valves are recessed and require removal of access panels.
In one Texas jobsite, a JLG 600S failed to start due to a corroded starter relay. The crew located the tow valves behind the front wheels, opened them, and used a skid steer to gently push the lift onto a trailer. The entire process took under 30 minutes and avoided damage.
Transporting the Lift Safely
Once the tow valves are open, the lift can be moved short distances. However, precautions must be taken:

• Use a rigid tow bar or push vehicle with soft contact points
  
• Avoid sharp turns or uneven terrain that could twist the frame
  
• Keep boom fully retracted and locked in transport position
  
• Use wheel chocks and tie-downs during loading
  
• Do not exceed 2–3 mph during movement
  

For long-distance transport, a tilt-bed trailer or lowboy is recommended. The lift should be winched or pushed onto the deck, not driven unless fully operational.
Hydraulic System Re-engagement After Tow
After the lift is moved and repaired, the tow valves must be closed to restore normal function. Failure to do so can result in:

• Loss of drive power
  
• Hydraulic fluid bypass during operation
  
• Overheating of the pump due to uncontrolled flow
  

Checklist:

• Close all tow valves clockwise until snug
  
• Check fluid levels and top off if needed
  
• Inspect for leaks around valve bodies
  
• Test drive function in a controlled area before returning to service
  

In one fleet, a technician forgot to close the tow valves after a repair. The lift moved sluggishly and overheated within minutes. Closing the valves and bleeding the system restored normal operation.
Alternative Solutions and Emergency Scenarios
If tow valves are inaccessible or damaged:

• Use dollies or wheel skates under each tire
  
• Lift the machine with a crane or forklift from designated lift points
  
• Remove drive motors and manually rotate hubs (only as last resort)
  
• Consult JLG technical support for model-specific instructions
  

Some newer models include electronic tow mode activation via onboard diagnostics. However, if the control module is dead, manual access remains essential.
Conclusion
Moving a non-operational JLG boom lift requires mechanical understanding, hydraulic caution, and proper tools. The tow valve is the key to safe relocation, protecting the drive system from damage and ensuring smooth transport. With methodical preparation and respect for hydraulic systems, even a dead lift can be moved without drama. In the world of aerial access, knowing how to tow is just as important as knowing how to rise.