Hitachi EXC270LC-5 Hydraulic Pump Issues and Maintenance

[MikePhua]

Introduction to the Hitachi EXC270LC-5
The Hitachi EXC270LC-5 is a powerful, mid-size hydraulic excavator that is widely used in construction, mining, and other heavy industries. Known for its durability and efficiency, this model is designed to deliver reliable performance in challenging work environments. It is powered by a fuel-efficient engine, and its hydraulic systems are designed for optimal performance, ensuring smooth operation in various applications, from digging to lifting and material handling.
However, as with any heavy machinery, the hydraulic system is crucial to the excavator's operation, and issues can arise if the hydraulic pump or components are not properly maintained. In this article, we will explore common hydraulic pump problems in the Hitachi EXC270LC-5, provide solutions to common issues, and discuss best practices for maintenance to ensure the longevity and efficiency of the hydraulic system.
Understanding the Hydraulic Pump System
Hydraulic pumps are an essential part of an excavator’s hydraulic system. They are responsible for converting the engine’s mechanical power into hydraulic energy, which is then used to drive various hydraulic cylinders and motors. The Hitachi EXC270LC-5’s hydraulic pump is a high-efficiency component that provides the necessary pressure to power the boom, arm, bucket, and other systems.
The hydraulic pump is typically a gear or piston pump, and it can either be a variable displacement pump, which adjusts the flow based on the load, or a fixed displacement pump, which provides a constant flow of hydraulic fluid.
Common Hydraulic Pump Issues in the Hitachi EXC270LC-5
The hydraulic pump system of the EXC270LC-5 can experience several common issues that may affect performance, including decreased hydraulic efficiency, unusual noises, or complete system failure. Identifying these issues early can help prevent extensive damage and ensure that the machine operates at optimal performance.

1. Decreased Hydraulic Power
   

A drop in hydraulic power can be one of the most common signs of a problem with the hydraulic pump. The operator may notice that the excavator is slower to respond, or that lifting, digging, or other hydraulic functions are not as powerful as usual. The main causes of this issue can include:

• Low hydraulic fluid levels
  
• Contaminated hydraulic fluid
  
• Worn or damaged pump components
  
• Leaks in the hydraulic lines
  

Solution: Check hydraulic fluid levels and ensure they are within the recommended range. If the fluid is contaminated, flush the system and replace the fluid. Inspect the pump for wear and tear, and replace any worn components as necessary.

1. Unusual Noises
   

Another issue that can indicate a problem with the hydraulic pump is the presence of unusual noises, such as whining, grinding, or knocking sounds. These noises may occur when the excavator is in operation or while idling, and they often point to issues such as:

• Air in the hydraulic system
  
• Cavitation (a condition where the hydraulic fluid vaporizes and forms bubbles inside the pump)
  
• Worn bearings or gears within the pump
  

Solution: If air is present in the hydraulic system, it could be due to a leak or low fluid levels. Check all hydraulic lines and seals for leaks, and ensure the system is fully pressurized. If cavitation is occurring, the problem may be linked to low fluid levels, the wrong type of hydraulic fluid, or issues with the pump's suction lines. In this case, replace or repair the pump components as necessary.

1. Overheating
   

Hydraulic systems are sensitive to temperature, and overheating can significantly reduce the efficiency and lifespan of the hydraulic pump. High temperatures can cause the hydraulic fluid to break down, leading to a loss of lubrication and eventual pump failure.
Solution: Ensure the machine is operating within the recommended temperature range. Check for blockages in the cooling system and clean or replace filters as needed. Regular maintenance of the cooling system and the hydraulic oil cooler is essential to preventing overheating.

1. Complete Pump Failure
   

In some cases, the hydraulic pump may fail completely, resulting in the loss of all hydraulic functions. Complete pump failure can be caused by:

• Worn or broken internal pump components
  
• Contaminated hydraulic fluid causing damage
  
• Lack of proper lubrication
  

Solution: If the pump fails, it will need to be replaced or repaired. Regular fluid changes, proper maintenance of components, and ensuring that the system is free of contaminants can help prevent total failure. Consider upgrading to higher-quality hydraulic components if your machine is older or has had previous issues with the pump.
Preventative Maintenance for the Hydraulic Pump
To ensure that the hydraulic pump of the Hitachi EXC270LC-5 operates at peak efficiency, it is essential to follow a comprehensive maintenance plan. Regular maintenance not only extends the life of the pump but also ensures that the excavator performs optimally on the job site.

1. Regular Fluid Inspections and Changes
   Hydraulic fluid is the lifeblood of the hydraulic system. Check the fluid levels regularly and top them off as needed. Perform fluid changes according to the manufacturer’s recommendations to prevent contamination and maintain proper lubrication.
   
2. Check for Leaks
   Inspect the hydraulic system for any signs of leaks, especially around the pump, valves, and hoses. Leaks can reduce system pressure and cause inefficiency. Tighten fittings, replace damaged hoses, and replace worn seals.
   
3. Monitor Hydraulic Filter Condition
   The hydraulic filters keep contaminants out of the system. Clogged or dirty filters can restrict fluid flow, leading to poor hydraulic performance. Clean or replace filters according to the maintenance schedule.
   
4. Pump Calibration
   Ensure that the hydraulic pump is calibrated properly for the machine's specifications. Improper calibration can result in inefficient operation, leading to premature wear on both the pump and other hydraulic components.
   
5. Use Recommended Fluids
   Always use the recommended hydraulic fluid that meets the specifications set by Hitachi. Using incorrect fluid can lead to damage to the pump and the overall hydraulic system.
   

Common Hydraulic System Problems and Solutions
While the hydraulic pump plays a significant role in the operation of the Hitachi EXC270LC-5, it is important to address other hydraulic system components that may also affect pump performance:

1. Hydraulic Motor Failure
   If the hydraulic motor is malfunctioning, it can place extra strain on the hydraulic pump. Ensure that the motor is in good condition and check for leaks or signs of wear.
   
2. Valve Issues
   Faulty or clogged valves can restrict the flow of hydraulic fluid, causing the pump to overwork. Clean or replace valves as needed to maintain smooth operation.
   
3. Suction Line Problems
   Suction lines that are clogged or damaged can reduce the pump’s ability to draw in fluid. Inspect suction lines regularly for blockages and leaks.
   

Conclusion
The hydraulic pump in the Hitachi EXC270LC-5 is crucial for ensuring smooth and efficient operation of the machine's various functions. By understanding common hydraulic pump issues, regularly performing maintenance tasks, and addressing problems promptly, operators can extend the lifespan of the excavator and maintain its performance on the job site. Regular inspections, proper fluid care, and addressing mechanical issues as soon as they arise will help keep the hydraulic system running efficiently, minimizing downtime and reducing repair costs.