Troubleshooting Hydraulic Pump Issues in the Volvo EC35 Excavator

[MikePhua]

The Volvo EC35 is a popular compact excavator known for its maneuverability and powerful hydraulic system. As with any heavy machinery, the hydraulic pump plays a crucial role in the overall operation, powering various systems like the arm, boom, and bucket. However, when hydraulic pump issues arise, it can lead to reduced performance, increased wear, or even complete operational failure. In this article, we’ll explore common hydraulic pump problems in the Volvo EC35, the signs to look out for, and how to effectively troubleshoot and resolve these issues.
Understanding the Role of the Hydraulic Pump in the EC35
The hydraulic pump in an excavator like the Volvo EC35 is responsible for converting mechanical energy from the engine into hydraulic energy. This hydraulic energy is used to power the machine's various hydraulic functions, such as lifting, tilting, digging, and rotating the excavator's arm.
The EC35 uses a variable displacement hydraulic pump, which adjusts the flow of hydraulic fluid based on the needs of the system. This feature provides improved fuel efficiency and allows the machine to perform a variety of tasks at different power levels.
Symptoms of Hydraulic Pump Problems in the EC35
When the hydraulic pump starts to malfunction, it can cause a range of issues. Here are some common symptoms to watch for:
1. Loss of Hydraulic Power

• Cause: One of the most noticeable symptoms of a failing hydraulic pump is a loss of hydraulic power. The excavator may struggle to lift heavy loads, operate the arm or bucket, or maintain consistent hydraulic pressure.
  
• Solution: This may be caused by a drop in fluid pressure due to pump wear, internal leaks, or a clogged filter. Inspect the hydraulic fluid levels and check for any fluid leaks. If the fluid is low, top it up, and check for blockages in the system. If power loss persists, the pump may need to be replaced or repaired.
  

2. Unusual Noises

• Cause: A malfunctioning hydraulic pump often makes unusual sounds, such as whining, grinding, or banging. These sounds typically indicate that the pump is working harder than it should be, possibly due to internal damage or contamination.
  
• Solution: Check for any debris or contamination in the hydraulic fluid, as this can damage the pump's internal components. If noise continues, consider draining the hydraulic fluid, cleaning the system, and replacing any worn parts within the pump. If the noise persists after cleaning, the pump may need to be replaced.
  

3. Overheating

• Cause: Hydraulic pumps generate heat as they operate. However, excessive heat can indicate a malfunctioning pump or an issue with the cooling system, such as a clogged radiator or low fluid levels.
  
• Solution: Check the hydraulic fluid for contamination and ensure it is at the correct level. If the fluid is excessively hot, it may be due to a failing pump or excessive friction in the system. Clean the cooling system and ensure the pump is operating correctly.
  

4. Erratic Operation of the Boom or Arm

• Cause: If the boom or arm of the excavator operates inconsistently or moves too slowly, this could indicate a problem with the hydraulic pump. This may be due to insufficient flow or pressure, or a malfunctioning valve.
  
• Solution: Inspect the pump and hydraulic lines for any leaks, blockages, or damage. If the system is clean and free of debris, the pump’s internal components may need to be inspected and replaced.
  

Common Causes of Hydraulic Pump Failure in the Volvo EC35
Understanding the underlying causes of hydraulic pump issues can help you take proactive measures to prevent problems and minimize downtime. Some common causes of hydraulic pump failure include:
1. Contaminated Hydraulic Fluid

• Cause: Contaminants such as dirt, water, or metal shavings can enter the hydraulic system and damage the pump’s internal components. Contaminated fluid causes excessive wear, reduces lubrication, and may lead to pump failure.
  
• Solution: Always use clean hydraulic fluid and replace it according to the manufacturer’s recommendations. Install hydraulic fluid filters and regularly inspect and replace them to prevent contamination.
  

2. Low Hydraulic Fluid Levels

• Cause: Low fluid levels can cause the hydraulic pump to suck in air, leading to cavitation. Cavitation occurs when air bubbles form within the fluid and collapse, causing damage to the pump and other components.
  
• Solution: Ensure the hydraulic fluid is topped up to the correct level. Check for leaks in the system that could cause fluid loss, and replace any damaged seals, hoses, or components.
  

3. Excessive Load or Overuse

• Cause: Continuously overloading the machine or using it for extended periods without proper rest can put excessive strain on the hydraulic pump. This can cause overheating, wear, and eventual failure.
  
• Solution: Avoid overloading the machine, and always operate it within its specified limits. Provide adequate rest periods to allow the hydraulic system to cool down, especially during heavy tasks.
  

4. Improper Maintenance

• Cause: Lack of regular maintenance, such as not changing the hydraulic fluid or neglecting to replace worn components, can lead to the degradation of the hydraulic pump over time.
  
• Solution: Follow the manufacturer’s maintenance schedule to ensure that the hydraulic system is in good working order. Regularly change the hydraulic fluid and replace any worn seals, filters, or components.
  

5. Improper Installation

• Cause: Incorrect installation of the hydraulic pump or components can lead to poor alignment, excessive wear, or even pump failure.
  
• Solution: Ensure that the hydraulic pump is properly installed and aligned according to the manufacturer's guidelines. Use the correct tools and follow the installation procedures to avoid errors.
  

Diagnostic Steps to Identify Hydraulic Pump Problems
If you suspect a hydraulic pump issue, follow these diagnostic steps to pinpoint the problem:

1. Check Fluid Levels and Quality: Ensure that the hydraulic fluid is at the correct level and that it is clean. Dirty or low fluid can cause poor pump performance.
   
2. Inspect for Leaks: Examine the hydraulic hoses, fittings, and seals for any signs of leaks. Leaks can cause a loss of pressure, leading to pump failure.
   
3. Listen for Unusual Sounds: Pay attention to any unusual noises coming from the pump or hydraulic system. Grinding or whining sounds may indicate internal pump damage.
   
4. Test Hydraulic Pressure: Use a pressure gauge to check the system’s hydraulic pressure. Low or fluctuating pressure can be an indicator of a pump issue.
   
5. Check for Overheating: Monitor the temperature of the hydraulic fluid. Overheating may indicate a malfunctioning pump or excessive friction within the system.
   
6. Inspect the Pump Internals: If you suspect internal damage, inspect the pump’s components, including the gears, bearings, and seals. Look for signs of wear, cracks, or contamination.
   

Solutions and Repair Options
If you identify a problem with the hydraulic pump, here are some potential solutions:

1. Pump Replacement: If the pump is severely damaged, replacement may be necessary. Consult with a certified Volvo dealer to ensure you use a genuine replacement pump.
   
2. Cleaning and Servicing: If the pump is clogged or contaminated, it may be possible to clean and service it. This could involve flushing the system, replacing filters, and addressing any internal wear.
   
3. Seals and Component Replacement: If leaks are the cause of the problem, replace the damaged seals or components, including hoses, fittings, and valves.
   
4. Regular Maintenance: Once the issue is resolved, follow the manufacturer’s maintenance schedule to prevent future problems. Regular fluid changes, filter replacements, and inspections can extend the life of your hydraulic system.
   

Preventative Maintenance Tips for the Volvo EC35 Hydraulic System
To avoid hydraulic pump problems and ensure the longevity of the Volvo EC35’s hydraulic system, follow these preventative maintenance tips:

• Change the Hydraulic Fluid Regularly: Follow the manufacturer’s recommendations for fluid changes, typically every 2,000 to 3,000 hours of operation, or as specified in the owner’s manual.
  
• Replace Filters and Seals: Regularly replace hydraulic filters and seals to prevent contamination and leaks.
  
• Monitor Fluid Temperature: Keep an eye on the hydraulic fluid temperature during operation, especially during heavy tasks, and allow the machine to cool down when necessary.
  
• Inspect Hydraulic Lines: Routinely inspect hydraulic hoses and lines for signs of wear, abrasions, or leaks, and replace them as needed.
  
• Avoid Overloading the Machine: Stick to the recommended load limits and avoid prolonged use at maximum capacity to prevent strain on the hydraulic system.
  

Conclusion
Hydraulic pump issues in the Volvo EC35 can significantly affect the machine's performance and productivity. By understanding the common symptoms and causes of pump failure, operators can quickly identify and resolve problems before they lead to costly repairs or downtime. Regular maintenance, along with proper operation and care, will help ensure that the hydraulic system remains in optimal condition, extending the lifespan of both the pump and the excavator itself.