Understanding Auxiliary Hydraulics in the Kubota U-35: Troubleshooting and Solutions

[MikePhua]

When dealing with compact excavators like the Kubota U-35, understanding how to properly use and troubleshoot the auxiliary hydraulics system is crucial for efficiency and avoiding costly repairs. Many operators face issues with the auxiliary hydraulics not responding, which can stem from a variety of causes, ranging from simple electrical faults to more complex hydraulic system malfunctions.
Auxiliary Hydraulics Overview
The auxiliary hydraulics system on the Kubota U-35, as with other compact excavators, is designed to power attachments like augers, breakers, or other tools that require hydraulic power. The system includes a hydraulic pump, control valves, hoses, and quick couplers, which allow quick attachment changes. Understanding how this system operates is key to diagnosing any issues.
Common Issues with Auxiliary Hydraulics on the Kubota U-35
One of the most common issues operators report is that the auxiliary hydraulics on the Kubota U-35 stop responding. This could be due to various reasons such as:

• Hydraulic fluid contamination: Dirty or low hydraulic fluid can impair the system’s performance.
  
• Valve failure: A malfunctioning control valve might not engage the hydraulics properly.
  
• Faulty connections: Leaking or loose hydraulic lines can result in a loss of pressure, making it difficult for the auxiliary hydraulics to function.
  

Troubleshooting Steps for Kubota U-35 Aux Hydraulics

1. Check the Hydraulic Fluid: Start by checking the fluid levels and quality. The fluid should be clean and at the proper level. If the fluid appears dirty or low, it could cause blockages or insufficient pressure.
   
2. Inspect the Control Valves: If the fluid is fine, check the control valves. A sticking valve can prevent the flow of hydraulic oil to the attachment, leaving the system unresponsive.
   
3. Examine the Electrical Components: Since the U-35 uses electric controls for its hydraulic systems, inspect the solenoids, switches, and wiring for any visible damage. A simple short circuit or loose wire could be the cause of the issue.
   
4. Test the Pressure Relief Valve: The pressure relief valve is another critical component. If it is set too low or if it’s malfunctioning, the hydraulic pressure may not be enough to power attachments.
   
5. Check for Leaks: Hydraulic leaks, even small ones, can significantly reduce the system’s efficiency. Examine all hoses, fittings, and connectors for leaks.
   

Real-Life Example: Solving Hydraulic Issues in the Field
A user on a Kubota forum reported a situation where their U-35’s auxiliary hydraulics stopped working entirely. After checking the system, they found that the hydraulic fluid had become contaminated with dirt due to improper filtration during maintenance. After flushing the system and replacing the fluid, the hydraulics began functioning again. This highlights the importance of using clean, high-quality hydraulic fluid and maintaining good filtration.
Preventive Measures and Maintenance
To prevent future hydraulic failures, operators should follow a routine maintenance schedule that includes:

• Regular fluid changes
  
• Inspection and cleaning of hydraulic filters
  
• Proper storage of the machine to prevent contamination
  
• Checking for leaks before every use
  

Conclusion
Auxiliary hydraulics are vital to the efficiency of compact excavators like the Kubota U-35. By regularly maintaining the system, troubleshooting common issues, and being aware of potential failures, operators can ensure that their machinery operates smoothly, thus minimizing downtime and costly repairs. Whether it's a simple issue like low fluid levels or a more complex problem with the control valves, a systematic approach to troubleshooting can often save time and money in the long run.