Troubleshooting the Lull 644 Highlander 2: Common Issues and Solutions

[MikePhua]

The Lull 644 Highlander 2 telehandler is a versatile machine widely used in construction, warehouses, and material handling. Known for its ability to lift heavy loads and reach significant heights, it has become a key piece of equipment on many job sites. However, like any complex piece of machinery, the Lull 644 Highlander 2 is not immune to occasional technical issues. Operators and fleet managers may encounter problems that require timely troubleshooting to ensure maximum uptime and productivity.
This article delves into some common problems faced by users of the Lull 644 Highlander 2, providing detailed insights into the causes of these issues and offering solutions to address them.
Overview of the Lull 644 Highlander 2
The Lull 644 Highlander 2 is a robust telehandler, designed for lifting, moving, and placing materials in hard-to-reach places. With a maximum lifting capacity of 6,000 pounds and a lift height of up to 44 feet, this machine is especially useful in construction settings where heavy loads need to be elevated or moved across uneven terrain. The Highlander 2 series includes several advanced features such as four-wheel drive, a versatile steering system (including crab steer, front steer, and rear steer), and a powerful engine, making it a favorite among professionals in the construction and industrial sectors.
Common Issues with the Lull 644 Highlander 2
While the Lull 644 Highlander 2 is a reliable machine, there are several recurring issues that operators and technicians often encounter. The following are some of the most common problems, along with their potential causes and solutions.
1. Engine Starting Problems
One of the most frequent issues with the Lull 644 Highlander 2 is difficulty starting the engine. When this occurs, it can halt operations and lead to unnecessary downtime. The causes of starting issues are often related to the fuel system, battery, or starter motor.
Possible Causes:

• Weak Battery: A weak or dead battery is the most common cause of engine starting problems. Extreme temperatures or an old battery can cause it to lose its charge.
  
• Faulty Starter Motor: If the starter motor is malfunctioning, it will prevent the engine from turning over.
  
• Fuel Delivery Issues: Blockages in the fuel lines, a clogged fuel filter, or a malfunctioning fuel pump can disrupt the flow of fuel, making it difficult for the engine to start.
  

Solutions:

• Check and Replace the Battery: Ensure that the battery is fully charged. If it’s old or failing, replacing it can resolve the issue.
  
• Inspect the Starter Motor: Test the starter motor by listening for clicking sounds when attempting to start the engine. If it’s defective, replacement may be necessary.
  
• Check the Fuel System: Inspect the fuel lines for leaks, and replace the fuel filter if it’s clogged. Make sure the fuel pump is functioning correctly and that there’s an adequate supply of clean fuel.
  

2. Hydraulic System Malfunctions
Hydraulic issues can manifest in several ways, from slow or jerky movements to complete loss of power in the boom or forks. Given the Lull 644 Highlander 2's reliance on hydraulics for lifting and reaching, these malfunctions can severely limit its functionality.
Possible Causes:

• Low Hydraulic Fluid Levels: Low fluid levels can cause the system to underperform or fail.
  
• Leaking Hydraulic Hoses: Hydraulic hose leaks are common and can lead to a drop in pressure, affecting the machine’s lifting ability.
  
• Faulty Hydraulic Pump: A damaged or worn hydraulic pump will not generate enough pressure to power the system properly.
  
• Contaminated Hydraulic Fluid: Dirt, debris, or water in the hydraulic fluid can damage components and clog filters.
  

Solutions:

• Check Fluid Levels: Ensure that the hydraulic fluid is at the recommended level. If the fluid is low, top it off with the appropriate type of fluid.
  
• Inspect for Leaks: Check all hydraulic hoses and fittings for visible leaks. Replace damaged hoses or fittings to restore pressure.
  
• Test the Hydraulic Pump: If the pump is not working efficiently, it may need to be rebuilt or replaced. Hydraulic systems can be tested using specialized equipment to verify pressure output.
  
• Change the Hydraulic Fluid: If the fluid is contaminated, replace it with fresh fluid and install a new filter to protect the system from further damage.
  

3. Transmission Issues
The transmission system in the Lull 644 Highlander 2 ensures that power is efficiently transferred from the engine to the wheels. When problems arise, they can cause loss of power or difficulty in moving the machine.
Possible Causes:

• Low Transmission Fluid: Just like the hydraulic system, low fluid levels in the transmission can cause slipping, poor shifting, or even total failure.
  
• Worn Transmission Components: Over time, the transmission's gears, seals, or clutches can wear out, leading to difficulty in engaging gears or unexpected slippage.
  
• Clogged Transmission Filter: A clogged filter can restrict fluid flow and reduce transmission performance.
  

Solutions:

• Check Fluid Levels: Make sure that the transmission fluid is within the specified range. Add more fluid if necessary, but be sure to use the correct type for the Lull 644.
  
• Inspect Transmission Components: If the fluid is clean and at the right level but problems persist, inspect the transmission for worn components such as gears, bearings, or seals.
  
• Replace the Transmission Filter: If the filter is dirty, replace it to improve fluid flow and performance.
  

4. Electrical System Failures
Electrical failures, such as issues with lights, alarms, or the control panel, can hinder the machine's ability to operate efficiently or indicate problems with the machine’s systems.
Possible Causes:

• Blown Fuses: A blown fuse can interrupt electrical circuits, causing certain functions or instruments to fail.
  
• Faulty Wiring or Connections: Corroded or loose connections can cause electrical components to stop working.
  
• Defective Alternator: If the alternator is not charging the battery properly, the machine may experience electrical shortages or failure to start.
  

Solutions:

• Inspect Fuses: Check all fuses for damage and replace any that are blown.
  
• Check Wiring: Inspect the wiring harness for loose connections, frayed wires, or signs of corrosion. Tighten or replace any faulty connections.
  
• Test the Alternator: Use a multimeter to check the output of the alternator. If it’s not providing adequate charge, consider replacing it.
  

5. Uneven Load Distribution or Lifting Problems
The Lull 644 Highlander 2 is designed to lift heavy loads, but uneven lifting or difficulty maintaining balance during operation can lead to safety hazards or equipment malfunction.
Possible Causes:

• Improper Load Distribution: Overloading or unevenly distributed loads can cause the machine to tip over or lose lifting capability.
  
• Damaged Stabilizers: The machine's stabilizers are crucial for providing balance during lifting. If they’re damaged or not functioning correctly, lifting can become unstable.
  
• Out of Calibration: The lifting arms or forks might need recalibration to ensure proper operation.
  

Solutions:

• Check Load Distribution: Always ensure that loads are evenly distributed on the forks, with the heaviest items placed as close to the machine as possible.
  
• Inspect Stabilizers: Verify that the stabilizers are fully extended and in good condition. Replace any damaged stabilizer components.
  
• Recalibrate the Lifting System: If lifting issues persist, recalibrate the lifting arms to factory specifications.
  

Conclusion
The Lull 644 Highlander 2 telehandler is a reliable and powerful piece of machinery, but like any machine, it requires proper care and timely maintenance to ensure optimal performance. By understanding the common issues that can arise—from engine starting problems to hydraulic system malfunctions—operators can take proactive measures to maintain the equipment and avoid costly repairs. Whether it’s troubleshooting electrical failures, addressing hydraulic leaks, or ensuring the transmission is in top condition, a systematic approach to diagnostics and repair will keep the Lull 644 Highlander 2 running smoothly on the job site.