Hitachi EX100-2 Pump Problems: Troubleshooting and Solutions

[MikePhua]

Introduction:
The Hitachi EX100-2 is a well-regarded model in the construction and excavation industries. Known for its reliability and efficiency, the EX100-2 has been a go-to choice for contractors needing a compact, versatile excavator. However, like any piece of machinery, it can experience issues over time. One of the most common problems reported by owners of the EX100-2 is pump failure or malfunction, which can severely impact the machine's hydraulic system and overall performance. In this article, we’ll explore the common causes of pump issues in the EX100-2, share real-world troubleshooting steps, and offer tips for repair and prevention.
Common Symptoms of Pump Problems in the Hitachi EX100-2

1. Loss of Hydraulic Power:
   A common indication that the hydraulic pump on the EX100-2 is failing is a noticeable loss of power. The machine might struggle to lift heavy loads or operate its attachments with full efficiency. This can be caused by issues like low hydraulic fluid levels, pump wear, or clogged filters.
   Story from the Field: One operator reported that their EX100-2 suddenly became sluggish, especially when lifting or rotating. They initially thought it was a fluid issue, but after checking and topping up the hydraulic fluid, the problem persisted. Further inspection revealed that the hydraulic pump was struggling to maintain pressure, which required professional attention to resolve.
   
2. Unusual Noises from the Pump:
   A hydraulic pump that’s beginning to fail often makes unusual noises, such as whining or grinding. These noises can signal that internal components of the pump are wearing out or that air is trapped in the hydraulic system, causing erratic pump performance.
   Example from the Forum: A forum user experienced a loud whining noise coming from their EX100-2’s pump, which was a sign of air in the hydraulic lines. After purging the system and inspecting for leaks, the noise subsided, and the machine's hydraulic performance returned to normal. However, the operator realized that this issue could recur if the pump was not repaired or replaced soon.
   
3. Overheating Hydraulic System:
   When the hydraulic pump begins to fail, it often leads to overheating of the hydraulic fluid. This can cause the system to operate inefficiently and increase the wear on the pump, seals, and hoses. Overheating can also lead to complete pump failure if not addressed in a timely manner.
   Real-Life Example: An operator noticed that the hydraulic oil temperature was rising rapidly, even during moderate usage. After a thorough inspection, they found that the pump’s internal seals were damaged, allowing oil to bypass the piston assembly. The excessive pressure buildup led to the overheating issue. Replacing the pump’s seals and conducting a full flush of the hydraulic system resolved the overheating problem.
   

Troubleshooting and Repairing the Hydraulic Pump

1. Check Hydraulic Fluid Levels and Quality:
   Before diving into pump repairs, the first step is to check the hydraulic fluid levels and its condition. Low fluid levels can cause pump cavitation, which leads to a lack of pressure and poor performance. Additionally, contaminated fluid can damage the pump and other components in the hydraulic system.
   Tip from Experienced Operators: Regularly check the hydraulic fluid to ensure it’s clean and at the proper level. Replace the fluid if it appears dirty or contaminated. This simple step can prevent many hydraulic issues, including pump failure.
   
2. Inspect the Hydraulic Lines and Filters:
   If the fluid levels are fine, the next step is to check the hydraulic lines and filters. Clogged filters or damaged hoses can restrict the flow of fluid, which can cause the pump to overwork and fail prematurely. Always replace the filters and repair any leaks in the hydraulic lines.
   Example from the Forum: One user found that their EX100-2 was experiencing intermittent hydraulic issues, which they initially attributed to a failing pump. However, after inspecting the hydraulic filters, they found that one of the filters was completely clogged, which restricted the flow of fluid to the pump. Replacing the filter resolved the issue without requiring a new pump.
   
3. Listen for Unusual Noises and Check for Vibration:
   If you notice strange noises or vibrations coming from the pump, it could be a sign of cavitation or internal wear. The best approach here is to listen carefully to the pump while the machine is operating, and use vibration sensors to detect any abnormal movements that could point to a malfunctioning pump.
   Forum Tip: A user shared that they used a stethoscope to listen to their hydraulic pump while it was running. The stethoscope helped them identify a consistent clicking sound coming from the pump, indicating internal damage to the pump’s pistons. Upon further inspection, they confirmed the pump needed to be replaced.
   
4. Pressure Testing:
   If the above steps don’t resolve the problem, pressure testing the hydraulic system is necessary to determine whether the pump is still functioning at the proper pressure levels. If the pump’s output pressure is lower than it should be, it may be time to replace or rebuild the pump.
   Real-Life Insight: One experienced technician mentioned that using a pressure gauge is critical when troubleshooting hydraulic pumps. By monitoring the system’s pressure, you can identify if the pump is underperforming and whether it needs repair or replacement.
   

How to Repair or Replace the Pump

1. Pump Rebuild vs. Replacement:
   Once you’ve determined that the hydraulic pump is indeed the source of the problem, the next decision is whether to rebuild the existing pump or replace it. If the pump is relatively new and the damage is limited, rebuilding may be a cost-effective solution. However, if the pump is old or severely damaged, replacing it entirely may be the better option.
   Tip from a Forum User: One operator shared that they chose to rebuild their EX100-2’s hydraulic pump rather than replacing it. By having the pump professionally rebuilt, they were able to save a significant amount of money, and the pump continued to perform like new after the rebuild.
   
2. Replacing the Pump:
   If you opt to replace the pump, make sure to source a genuine replacement part from a reputable supplier. While aftermarket parts might save money initially, they can often lead to more problems down the line. Always ensure compatibility between the replacement pump and the hydraulic system to avoid future complications.
   Example from the Field: A forum user emphasized the importance of purchasing parts from trusted suppliers. They found that after-market pumps didn’t meet the same quality standards as OEM parts, which led to faster wear and tear. They now only use original Hitachi replacement pumps to avoid such issues.
   
3. Installation and Calibration:
   When installing a new or rebuilt pump, proper installation is crucial to ensure that the pump operates correctly. Ensure all fittings, seals, and connections are tight, and calibrate the system to the manufacturer’s specifications. If you’re unsure about the process, it’s advisable to have a qualified technician handle the installation.
   Forum Tip: One user mentioned that after installing their new pump, they had to recalibrate the system to match the factory pressure settings. This final step ensured that the hydraulic system was running optimally.
   

Preventative Maintenance for the Hitachi EX100-2

1. Regular Fluid and Filter Changes:
   Keeping the hydraulic fluid clean and at the right levels is one of the simplest ways to prevent pump failure. Regular fluid and filter changes will not only extend the life of the pump but also improve the overall efficiency of the machine.
   
2. Routine Inspection of Hydraulics:
   Perform routine inspections of the hydraulic system, checking for leaks, wear, or any signs of damage. Catching small issues early on can prevent costly repairs down the line.
   
3. Monitor Pump Performance:
   Always monitor the performance of the hydraulic pump during operation. Any unusual noises or signs of sluggish performance should be investigated immediately before they develop into more significant problems.
   

Conclusion:
Pump issues in the Hitachi EX100-2, while frustrating, are not uncommon, especially as the machine ages. By understanding the signs of hydraulic pump problems and taking proactive steps to troubleshoot and repair the system, you can significantly extend the life of the machine and avoid costly breakdowns. Whether you're dealing with low pressure, noise, or overheating, it's important to act quickly and consult with experts when necessary. Through careful maintenance, proper fluid management, and timely repairs, your EX100-2 can continue to perform reliably for years to come.