JLG 40HA Boom Synchronization: Troubleshooting and Solutions

[MikePhua]

The JLG 40HA articulating boom lift, produced between 1990 and 1998, is renowned for its versatility and robust performance on construction sites. However, like all machinery, it can experience issues over time. One common problem reported by operators is the desynchronization of the tower boom, where the upright portion of the boom fails to align correctly when stowed. This misalignment can lead to operational difficulties and potential safety concerns.
Understanding the Synchronization Mechanism
The JLG 40HA utilizes a hydraulic system to control the movement and synchronization of its booms. Hydraulic cylinders, controlled by valves and manifolds, work in tandem to ensure that both the primary and tower booms move simultaneously and maintain proper alignment. The synchronization process is crucial for the machine's stability and functionality.
Common Causes of Desynchronization
Several factors can contribute to the desynchronization of the tower boom:

• Hydraulic Hose Issues: A broken or damaged hydraulic hose can disrupt the flow of fluid, leading to unequal movement between the booms. Replacing the damaged hose with one of the correct specification is essential.
  
• Valve Malfunctions: The synchronization valve, often identified by a red pull knob, plays a pivotal role in aligning the booms. If this valve is missing, relocated, or malfunctioning, it can cause misalignment. Inspecting the hydraulic manifold or control block for alternative adjustment points is recommended.
  
• Cylinder Wear or Damage: Worn or damaged cylinders can lead to uneven movement. Regular inspection and maintenance are necessary to identify and address such issues promptly.
  

Troubleshooting and Re-Synchronization Procedures
To address synchronization issues, operators can follow these steps:

1. Raise the Main Boom: Elevate the main boom to a height of approximately 6 to 10 feet.
   
2. Engage the Red Knob: Pull out and hold the red synchronization valve located near the hydraulic tank.
   
3. Lower the Tower Boom: While holding the red knob, lower the tower boom completely.
   
4. Release the Red Knob: Once the tower boom is fully lowered, release the red knob.
   
5. Repeat if Necessary: If the tower boom does not align correctly, repeat the procedure.
   

In cases where the red knob does not resolve the issue, inspecting the hydraulic system for leaks, blockages, or faulty components is essential. Utilizing diagnostic tools can aid in identifying underlying problems.
Preventive Maintenance Tips
To minimize the risk of synchronization issues:

• Regular Inspections: Conduct routine checks of hydraulic hoses, cylinders, and valves for signs of wear or damage.
  
• Proper Storage: Store the lift in a dry, temperature-controlled environment to prevent cold-related issues.
  
• Use Correct Hydraulic Fluids: Ensure that the hydraulic system is filled with the manufacturer's recommended fluid to maintain optimal performance.
  
• Training: Educate operators on the importance of the synchronization valve and the correct procedures for its use.
  

Conclusion
The JLG 40HA boom lift is a valuable asset on construction sites, but like all machinery, it requires regular maintenance and attention to ensure optimal performance. Understanding the synchronization system and addressing issues promptly can extend the lifespan of the equipment and enhance safety on the job site.