Bobcat 843 Bucket Control Troubles: Diagnosing and Resolving Common Issues

[MikePhua]

The Bobcat 843, a versatile skid-steer loader, is a workhorse for construction, landscaping, and other heavy-duty applications. One of the critical components of the Bobcat 843 is its bucket control system, which allows operators to precisely manipulate the bucket for digging, lifting, and carrying materials. However, like all mechanical systems, the bucket control can sometimes malfunction, causing frustration and downtime. Understanding the potential issues and troubleshooting techniques can help restore optimal performance to the Bobcat 843.
Understanding the Bobcat 843 Bucket Control System
The Bobcat 843 uses hydraulic controls to operate the bucket, which is driven by the loader’s hydraulic system. The system is composed of several components that work together to lift, tilt, and lower the bucket:

• Hydraulic Cylinder: This component is responsible for the actual movement of the bucket. It uses hydraulic fluid pressure to extend and retract, allowing for the lifting and lowering of the bucket.
  
• Hydraulic Valve: This controls the flow of hydraulic fluid to the hydraulic cylinder. It can be operated by a joystick or control lever inside the cabin.
  
• Control Linkages: These mechanical components connect the control valve to the hydraulic cylinder, translating the operator’s inputs into action.
  
• Pump and Reservoir: The hydraulic pump provides the necessary pressure, and the reservoir holds the hydraulic fluid.
  

Any malfunction in this system can affect the bucket’s ability to function properly, making it difficult to perform essential tasks.
Common Issues with the Bobcat 843 Bucket Control
Several problems can cause the bucket control system on the Bobcat 843 to malfunction. These issues typically fall into one of two categories: hydraulic system problems or control system malfunctions.

1. Weak or Slow Bucket Movement
   • Causes: One of the most common complaints from operators is that the bucket moves slowly or lacks the power it once had. This can happen if the hydraulic fluid is low or contaminated, the hydraulic pump is failing, or the hydraulic filter is clogged.
     
   • Symptoms: Slow or weak lifting, jerky movements, or an inability to lift heavy loads.
     
   • Solutions:
     • Check and refill the hydraulic fluid to the correct level.
       
     • Replace the hydraulic filter if clogged.
       
     • Inspect the hydraulic pump for wear and tear, and replace it if necessary.
       
2. Bucket Sticking or Not Moving
   • Causes: A stuck bucket can result from air trapped in the hydraulic system, a malfunctioning hydraulic valve, or faulty control linkages. It can also occur if there is a hydraulic fluid leak.
     
   • Symptoms: The bucket won’t lift or tilt, or it may get stuck in a certain position.
     
   • Solutions:
     • Bleed the hydraulic system to remove any trapped air.
       
     • Inspect the hydraulic valve for damage or wear and replace if necessary.
       
     • Check for fluid leaks, especially around hoses and fittings, and replace any damaged components.
       
3. Erratic or Unresponsive Bucket Control
   • Causes: An erratic or unresponsive bucket control can be caused by problems with the joystick or lever controls, faulty electrical connections, or issues with the control valve.
     
   • Symptoms: The bucket may respond unpredictably, or not at all, to the operator’s input.
     
   • Solutions:
     • Inspect the joystick or lever controls for wear, damage, or loose connections.
       
     • Check the electrical connections to ensure the system is receiving proper signals.
       
     • Test the control valve for proper operation and replace it if it’s faulty.
       
4. Hydraulic Fluid Leaks
   • Causes: Hydraulic fluid leaks can occur at any connection point, including hoses, fittings, and the hydraulic cylinder. These leaks can reduce the pressure in the system, leading to slow or inadequate bucket movement.
     
   • Symptoms: Visible hydraulic fluid around hoses, fittings, or under the machine.
     
   • Solutions:
     • Inspect all hydraulic hoses and fittings for signs of wear or cracks.
       
     • Tighten loose fittings or replace damaged hoses.
       
     • Check the hydraulic cylinder seals and replace them if necessary.
       

Preventive Maintenance Tips for the Bobcat 843 Bucket Control System
Preventing issues with the bucket control system requires regular maintenance and attention to detail. Here are some essential maintenance tips to ensure optimal performance:

• Regularly Check Hydraulic Fluid: Always ensure the hydraulic fluid is at the proper level and that it is clean. Contaminated or low fluid can lead to inefficient operation and eventual failure of hydraulic components.
  
• Inspect and Clean Hydraulic Filters: Dirty or clogged filters can restrict fluid flow and lead to poor bucket performance. Clean or replace filters at regular intervals.
  
• Lubricate Control Linkages: The control linkages can wear out over time, leading to stiff or unresponsive controls. Regular lubrication can help prevent this.
  
• Check for Leaks: Regularly inspect all hydraulic hoses and fittings for signs of wear or leaks. Early detection of leaks can prevent more serious problems later on.
  
• Perform Routine Hydraulic System Bleeding: Air in the hydraulic system can cause erratic bucket movement. Bleed the system regularly to ensure smooth and consistent operation.
  

Real-World Example: Troubleshooting the Bobcat 843
In one instance, a construction company in Texas was experiencing slow bucket movement on their Bobcat 843, which was hindering their ability to complete tasks efficiently. After checking the hydraulic fluid and finding it low, they topped up the system, but the problem persisted. A closer inspection revealed a clogged hydraulic filter, which was preventing proper fluid flow. Once the filter was replaced, the bucket’s performance improved, and the operator was able to resume work without further issues.
Conclusion
The Bobcat 843 is a powerful and reliable skid-steer loader, but like all heavy equipment, it requires regular maintenance and occasional troubleshooting to keep it operating smoothly. By understanding the common issues with the bucket control system and addressing them promptly, operators can avoid costly repairs and downtime. Regular inspections, preventive maintenance, and quick response to issues like low hydraulic fluid, leaks, or faulty components will ensure that the Bobcat 843 continues to perform at its best.