1997 Hitachi EX55-UR Excavator: A Detailed Review and Common Issues

[MikePhua]

The 1997 Hitachi EX55-UR is a compact yet robust mini-excavator designed for smaller-scale excavation projects. Popular for its versatility, maneuverability, and solid construction, it has been a preferred machine for tasks in urban construction sites, landscaping, and utility work. However, like any piece of heavy machinery, it is not without its challenges. In this article, we delve into the EX55-UR's performance, common problems, maintenance tips, and key features.
Overview of the Hitachi EX55-UR Excavator
The EX55-UR is a model within Hitachi's EX-UR series, a line known for its urban and confined-area capabilities. These excavators are designed with a short tail swing, allowing for excellent maneuverability in tight spaces—an essential feature for urban construction, roadwork, and landscaping. Despite being a smaller machine in comparison to larger excavators, the EX55-UR has a solid lifting capacity and powerful hydraulic system that makes it suitable for a variety of tasks.
Some of its key specifications include:

• Operating Weight: Approximately 5,500-6,000 kg (depending on configuration)
  
• Engine Power: Around 42-50 horsepower, depending on the engine model used
  
• Digging Depth: Around 3 meters (varies by arm configuration)
  
• Bucket Capacity: 0.18-0.21 cubic meters
  
• Hydraulic System Pressure: 220 bar
  

These features make it a reliable option for handling smaller excavating jobs, demolition work, and trenching.
Common Problems with the 1997 Hitachi EX55-UR
Although the EX55-UR is known for its solid performance, several issues are commonly reported by owners and operators. Here, we discuss the most frequently encountered problems and how to address them.
1. Hydraulic System Failures
One of the most common issues with older EX55-UR excavators is hydraulic system failure. Over time, the hydraulic system can experience wear, leading to loss of power, erratic operation, or complete failure of certain functions, such as the boom, bucket, or swing motor.
Potential Causes:

• Contaminated Hydraulic Fluid: Dirt and debris in the hydraulic fluid can cause blockages and damage to the system. This is particularly an issue if the oil hasn’t been changed regularly.
  
• Leaking Hydraulic Lines: The hydraulic lines can degrade over time, leading to leaks, which reduces the system's efficiency.
  

Solution:

• Regularly inspect hydraulic fluid levels and change the oil as recommended by the manufacturer.
  
• Check hydraulic lines for any signs of wear, cracks, or leaks. Replace any damaged hoses and seals to prevent further issues.
  

2. Swing Motor Malfunctions
Another common issue with the EX55-UR is malfunctioning of the swing motor. The swing motor controls the rotation of the upper structure of the excavator. If this motor fails, it can result in poor swing performance, or the machine may fail to rotate completely.
Symptoms:

• Sluggish or jerky swing motion
  
• Inability to rotate the upper portion of the machine
  

Solution:

• Check the swing motor for any obvious signs of damage or excessive wear.
  
• Inspect the hydraulic fluid levels, as low levels can reduce motor performance.
  
• If the motor is malfunctioning, it may need to be replaced or repaired by a qualified technician.
  

3. Electrical System Issues
As with many older machines, the electrical system in the 1997 Hitachi EX55-UR can experience various problems. Common issues include faulty wiring, malfunctioning sensors, or dead batteries.
Symptoms:

• Difficulty starting the machine
  
• Instrument panel lights malfunctioning
  
• Electrical systems (lights, wipers, etc.) not functioning properly
  

Solution:

• Inspect all wiring connections for corrosion or loose connections, particularly around the battery and alternator.
  
• Check the battery’s charge and replace it if it is no longer holding power.
  
• Clean and secure all electrical terminals to ensure proper contact.
  

4. Engine Overheating
Engine overheating is another issue that can occur in the EX55-UR. This is typically caused by a clogged radiator, old coolant, or problems with the fan or water pump.
Symptoms:

• The temperature gauge shows high readings
  
• Steam or smoke coming from the engine compartment
  

Solution:

• Flush the radiator and replace the coolant to keep the engine cool.
  
• Ensure that the cooling fan is functioning properly and isn’t obstructed by debris.
  
• Check the water pump and thermostat to ensure they are working efficiently.
  

5. Undercarriage Wear and Tear
The undercarriage is subject to constant stress from movement and contact with rough terrain. On the EX55-UR, the tracks, rollers, and sprockets can wear down, leading to poor performance or even failure of the undercarriage components.
Symptoms:

• Uneven track wear
  
• Noisy tracks or grinding sounds
  
• Difficulty in moving or uneven movements
  

Solution:

• Regularly inspect the undercarriage for any signs of wear or damage.
  
• Check the track tension and adjust it as necessary to prevent undue stress on the rollers and sprockets.
  
• Replace worn-out tracks, rollers, or sprockets to prevent further damage.
  

Maintenance and Care Tips
To keep the Hitachi EX55-UR running smoothly and avoid major breakdowns, regular maintenance is essential. Here are some general maintenance tips for the excavator:

1. Hydraulic System: Always use clean, high-quality hydraulic fluid and replace it as per the manufacturer's guidelines. Regularly check for leaks, and clean the hydraulic filters to ensure proper flow.
   
2. Engine Maintenance: Regular oil changes, air filter replacement, and spark plug checks are crucial for optimal engine performance. Keep the cooling system clean and topped up to avoid overheating.
   
3. Track and Undercarriage Maintenance: Monitor the tracks and undercarriage for wear. Proper track tension is important for preventing excessive wear and reducing the risk of costly repairs.
   
4. Electrical System: Regularly check all electrical components, especially the battery and wiring, to prevent electrical failures during operation.
   

Conclusion
The 1997 Hitachi EX55-UR is a versatile and powerful mini-excavator that has proven its value on construction sites and landscaping projects. However, as with any older equipment, it requires proper care and maintenance to ensure its continued reliability. By addressing common issues such as hydraulic system failures, swing motor malfunctions, and electrical problems promptly, operators can maximize the lifespan of their machine and keep it performing at its best. Regular maintenance, proactive repairs, and attention to wear and tear are the keys to keeping the EX55-UR running smoothly and avoiding costly downtime.