Hitachi EX55UR Problems: Common Issues and Solutions

[MikePhua]

Introduction to the Hitachi EX55UR Mini Excavator
The Hitachi EX55UR is a compact, versatile mini-excavator designed for a variety of construction and digging applications. Known for its efficiency and reliability, the EX55UR is frequently used in tight spaces where larger machines cannot operate. However, like all machinery, it can face problems that may affect its performance and reliability. In this article, we’ll discuss common issues reported with the Hitachi EX55UR, their potential causes, and suggested solutions to help operators keep their equipment in optimal working condition.
Common Issues with the Hitachi EX55UR Mini Excavator

1. Hydraulic System Problems
   Hydraulic issues are among the most common problems that owners face with the Hitachi EX55UR. These can manifest as a lack of power, sluggish movements, or complete failure of hydraulic functions, such as the boom, arm, or bucket operations.
   • Possible Causes:
     • Low or contaminated hydraulic fluid.
       
     • Worn-out hydraulic pumps or valves.
       
     • Leaking hydraulic hoses or seals.
       
   • Solutions:
     • Check and replace the hydraulic fluid if it’s low or contaminated. Ensure that the correct hydraulic fluid type is used.
       
     • Inspect all hydraulic hoses and seals for leaks and replace damaged components.
       
     • If the pump or valves are faulty, consider replacing them or seeking professional repairs.
       
2. Engine Starting Issues
   Some users report problems starting the engine, particularly in colder weather or after the machine has been in storage for a while. This could be due to several factors.
   • Possible Causes:
     • A weak or dead battery.
       
     • Fuel system issues, such as clogged fuel filters or dirty injectors.
       
     • Faulty glow plugs (especially in colder temperatures).
       
   • Solutions:
     • Ensure the battery is charged and in good condition. If it’s weak or faulty, replace it.
       
     • Check and replace the fuel filters, and clean or replace the fuel injectors if necessary.
       
     • Test the glow plugs and replace them if they aren’t working properly to ensure smooth starting in cold conditions.
       
3. Track and Undercarriage Problems
   Like many excavators, the EX55UR can experience issues with its tracks and undercarriage components. Symptoms of problems in this area include uneven track wear, track slippage, or difficulty steering.
   • Possible Causes:
     • Incorrect track tension or loose tracks.
       
     • Worn-out rollers or sprockets.
       
     • Improper alignment or lack of lubrication.
       
   • Solutions:
     • Adjust the track tension according to the manufacturer’s guidelines to ensure the tracks are properly fitted.
       
     • Inspect and replace worn-out rollers or sprockets. Regularly lubricate the undercarriage to reduce friction and wear.
       
     • Ensure the tracks are properly aligned and check for any obstructions or damage that might be causing slippage.
       
4. Electrical System Failures
   Electrical issues can also crop up in the EX55UR, with symptoms such as the machine failing to start, the display screen malfunctioning, or lights not working.
   • Possible Causes:
     • Loose or corroded electrical connections.
       
     • Faulty alternator or fuse.
       
     • Issues with the ECU (electronic control unit).
       
   • Solutions:
     • Inspect all electrical connections for corrosion or looseness and clean or tighten them as needed.
       
     • Check the alternator and replace any blown fuses.
       
     • If the ECU is suspected of malfunctioning, it may need to be reset or replaced by a professional technician.
       
5. Cooling System Problems
   Overheating is another common issue, especially in machines that work in hot climates or under heavy load for extended periods.
   • Possible Causes:
     • Low coolant levels.
       
     • Clogged radiator or cooling fins.
       
     • Faulty thermostat or water pump.
       
   • Solutions:
     • Check and top off the coolant if necessary. Ensure the coolant is fresh and free of contaminants.
       
     • Clean the radiator and cooling fins regularly to prevent blockages.
       
     • Test the thermostat and water pump, replacing them if necessary to maintain proper engine cooling.
       
6. Excessive Vibration and Noise
   If the EX55UR is experiencing excessive vibration or unusual noise during operation, this can indicate problems with the machine’s components.
   • Possible Causes:
     • Imbalanced tracks or undercarriage.
       
     • Worn-out bearings or bushings.
       
     • Loose or damaged parts in the engine or hydraulic system.
       
   • Solutions:
     • Inspect the tracks for any damage, wear, or imbalance and replace any damaged components.
       
     • Check the bearings and bushings in the undercarriage and replace any that are worn or damaged.
       
     • Tighten or replace any loose or damaged parts in the engine or hydraulic system.
       

How to Maintain the Hitachi EX55UR Mini Excavator
Regular maintenance is essential to keeping the EX55UR in top condition and preventing many of the issues mentioned above. Here are some general maintenance tips:

1. Regular Oil and Filter Changes:
   Follow the manufacturer's recommended intervals for oil and filter changes to keep the engine running smoothly.
   
2. Inspect Hydraulic Components:
   Periodically check hydraulic fluid levels, hoses, and seals. Replace any worn components before they cause further damage.
   
3. Monitor the Tracks:
   Keep an eye on the track tension and condition. Make adjustments and replace parts as needed to ensure proper movement.
   
4. Electrical System Checks:
   Inspect the electrical connections and clean them regularly to avoid corrosion and ensure reliable starting and operation.
   
5. Cooling System Maintenance:
   Ensure the cooling system is free of blockages and the coolant is topped off to avoid overheating during extended use.
   

Conclusion
The Hitachi EX55UR mini-excavator is a reliable piece of equipment, but like any machine, it may experience issues over time. By staying proactive with maintenance and addressing problems as they arise, operators can ensure their machine runs efficiently and remains operational for longer periods. Whether it’s hydraulic, electrical, or mechanical issues, diagnosing the problem quickly and making timely repairs can help prevent costly downtime and extend the life of the excavator.