Komatsu PC35MR-2 Swing and Blade Won't Move When Cold: Troubleshooting Tips

[MikePhua]

The Komatsu PC35MR-2 is a compact mini excavator widely used in various construction projects. However, like many pieces of machinery, it can sometimes experience issues, especially when starting up in cold conditions. One of the common problems reported by operators is that the swing and blade do not move when the machine is cold. This article outlines the potential causes and solutions to this issue, helping operators troubleshoot and get their machine back to optimal performance.
Common Symptoms of Swing and Blade Movement Problems

1. No Movement When Cold: The most noticeable symptom is that the swing and blade functions are unresponsive when the machine is cold. The operator may attempt to move the controls, but there is no reaction from the swing or blade systems.
   
2. Delayed Response After Warming Up: In some cases, after the machine warms up, the swing and blade may eventually begin to operate normally. This indicates that the issue may be related to cold temperatures affecting hydraulic fluid or system components.
   
3. Erratic or Slow Movement: Even if the swing or blade eventually begins to move after warming up, it may move slowly or erratically, suggesting that there could be an issue with the hydraulic system's performance under cold conditions.
   

Potential Causes for the Issue

1. Viscosity of Hydraulic Fluid: Hydraulic fluid is essential for the operation of the swing and blade mechanisms. Cold weather can cause the hydraulic fluid to thicken, increasing its viscosity. Thickened fluid moves more slowly, which can prevent the hydraulic cylinders from responding properly when the controls are engaged.
   
2. Low Hydraulic Fluid Levels: If the hydraulic fluid is too low, it can lead to poor performance, especially in colder temperatures. Low fluid levels can cause air to enter the hydraulic system, creating air pockets that prevent proper operation of the hydraulic components.
   
3. Hydraulic Filter Clogging: Over time, dirt and debris can accumulate in the hydraulic filter. A clogged filter can restrict fluid flow, especially when the fluid is cold and thicker. This can cause slow or unresponsive hydraulic movement, particularly for the swing and blade functions.
   
4. Cold Weather Effects on Hydraulic Components: In very cold weather, seals and valves within the hydraulic system can contract or become stiff, leading to improper engagement or delayed movement of the hydraulic actuators.
   
5. Pressure Relief Valve Issues: If the pressure relief valve is malfunctioning, it may not allow the hydraulic system to generate enough pressure to operate the swing or blade properly when the machine is cold.
   

How to Fix the Swing and Blade Movement Issue

1. Check and Replace Hydraulic Fluid: One of the first steps is to check the hydraulic fluid's condition and level. If the fluid is too thick or low, replace it with the recommended type and amount. It's essential to use the appropriate fluid for the operating temperature range.
   
2. Inspect the Hydraulic Filter: Check the hydraulic filter for any signs of clogging or contamination. If the filter is clogged, replace it with a new one. Regular filter maintenance is crucial to ensure smooth hydraulic operation.
   
3. Warm Up the Machine: Allow the machine to warm up in a sheltered area before using it. This can help reduce the viscosity of the hydraulic fluid and ensure the components operate smoothly. If the weather is consistently cold, consider using a hydraulic fluid designed for low-temperature environments.
   
4. Inspect Seals and Valves: If the machine is still having issues after warming up, inspect the seals and valves for any damage. Cold weather can cause seals to become brittle, leading to leaks or reduced performance. Damaged seals should be replaced to prevent further hydraulic system issues.
   
5. Check the Pressure Relief Valve: Test the pressure relief valve to ensure it is functioning correctly. If it is stuck or malfunctioning, it may prevent the system from building adequate pressure, which could explain the slow or unresponsive movement.
   

Preventative Measures
To prevent future issues with the swing and blade, it's crucial to conduct regular maintenance on the hydraulic system. Here are a few steps to help keep the system in top shape:

• Regularly check hydraulic fluid levels and replace the fluid as needed.
  
• Replace the hydraulic filter at recommended intervals to prevent clogging.
  
• Keep the machine sheltered during colder months to prevent excessive exposure to freezing temperatures.
  
• Use low-temperature hydraulic fluids if you frequently operate in cold conditions.
  

Conclusion
Issues with the swing and blade on a Komatsu PC35MR-2 can be frustrating, particularly when they occur in cold weather. By understanding the potential causes, such as thickened hydraulic fluid, low fluid levels, clogged filters, and cold-related seal issues, operators can troubleshoot and resolve these problems. Regular maintenance and proper care of the hydraulic system are essential for ensuring that the machine operates efficiently in all conditions. With the right approach, operators can keep their equipment running smoothly, even in colder temperatures.