Hitachi EX 120: Performance, Features, and Maintenance Insights

[MikePhua]

The Hitachi EX 120 is a part of the renowned EX series of hydraulic excavators produced by Hitachi Construction Machinery. This versatile and efficient piece of equipment has garnered attention for its robust performance, reliability, and cost-effectiveness. Since its release, the EX 120 has been used in a variety of construction, mining, and excavation projects, thanks to its impressive lifting capacity, strong digging power, and smooth operation.
In this article, we will explore the specifications, performance, common issues, and maintenance tips for the Hitachi EX 120. Additionally, we’ll take a look at the history behind the machine’s development, its success in the market, and how it fits into the broader context of the construction equipment industry.
Overview of the Hitachi EX 120
The Hitachi EX 120 is a medium-sized, tracked hydraulic excavator. With its powerful engine, precise hydraulics, and ergonomic design, it is well-suited for a variety of tasks, from digging and grading to lifting heavy materials and demolition work. The EX 120 is equipped with a powerful engine that delivers high efficiency, while its hydraulic system ensures smooth operation and a strong digging force.
Key Specifications:

• Engine Power: 75-85 kW (varies depending on the model and specific configuration).
  
• Operating Weight: Approximately 12,000–13,000 kg (depending on the configuration).
  
• Bucket Capacity: Typically 0.5–0.6 cubic meters, ideal for heavy digging tasks.
  
• Maximum Digging Depth: Around 6 meters, depending on arm configuration and attachments.
  
• Max Reach: 8 meters for certain arm configurations.
  
• Hydraulic System: Equipped with advanced hydraulics for precise control and enhanced efficiency.
  

Performance and Capabilities
The Hitachi EX 120 is designed to offer superior performance in various environments, whether it's working on a construction site, a demolition project, or an agricultural job. Its balanced design, coupled with a high-performing engine, allows it to offer reliable performance for various digging, lifting, and grading applications.

1. Digging and Excavation: The EX 120 is designed to handle tough excavation tasks. Its powerful digging force allows it to work efficiently in soil, rock, and gravel. With a strong bucket breakout force and arm force, the EX 120 can move large amounts of material, making it a go-to machine for projects requiring significant digging or trenching.
   
2. Stability and Maneuverability: Despite its compact size, the EX 120 is stable even in challenging conditions. Its undercarriage design ensures better balance and weight distribution, which is crucial for operating on uneven or sloped surfaces. The tracks are designed to provide ample traction, ensuring that the machine performs well in both soft and rocky terrains.
   
3. Hydraulic Performance: The hydraulic system in the EX 120 provides responsive controls and helps achieve precise digging and lifting. The system uses a load-sensing design to optimize hydraulic pressure, delivering excellent performance without wasting fuel.
   
4. Fuel Efficiency: A notable feature of the Hitachi EX 120 is its fuel-efficient operation. The engine and hydraulic system are designed to minimize fuel consumption, making it an economical choice for long-duration projects.
   

Common Issues with the Hitachi EX 120
While the Hitachi EX 120 is a robust machine, like any piece of heavy equipment, it is susceptible to certain issues, especially with prolonged use. Here are some common issues reported by users:

1. Hydraulic System Leaks: Over time, the hydraulic hoses and seals may begin to wear out, leading to leaks. These leaks can affect the overall performance of the machine and result in loss of hydraulic pressure. Regular inspections are recommended to detect leaks early and replace worn-out components promptly.
   
2. Undercarriage Wear: The undercarriage of the EX 120, which includes the tracks, rollers, and sprockets, can wear down with extensive use. This can lead to reduced traction, slower movement, and increased maintenance costs. Ensuring that the tracks are properly tensioned and the undercarriage is regularly serviced can help extend its lifespan.
   
3. Engine Performance Issues: Users have sometimes reported reduced engine performance, particularly under heavy load. This can be attributed to fuel system issues, clogged air filters, or worn-out components. Regular servicing and timely replacement of air filters and fuel filters are essential to keep the engine running smoothly.
   
4. Electrical Failures: As with many modern machines, electrical issues can sometimes arise in the EX 120, such as malfunctioning sensors or faulty wiring. These problems may affect the operation of the machine’s control system, resulting in errors or unexpected behavior. Routine electrical inspections are important to detect potential issues early.
   
5. Overheating: If the cooling system is not properly maintained, the machine may overheat, especially during extended use in hot conditions. Checking the radiator, coolant levels, and fan operation regularly is crucial for preventing overheating issues.
   

Maintenance and Care for the Hitachi EX 120
To ensure the Hitachi EX 120 continues to perform at its best, it is crucial to adhere to a regular maintenance schedule. Here are some essential maintenance tips to help maximize the lifespan and efficiency of the machine:

1. Engine and Oil Maintenance: The engine oil should be changed regularly to prevent wear and tear on the internal engine components. Also, ensure that the fuel filters are cleaned or replaced as needed to avoid fuel system blockages. Regularly checking the coolant system and keeping it at optimal levels is crucial to prevent overheating.
   
2. Hydraulic System Checks: Inspect the hydraulic system frequently for any signs of leaks or damage. It is essential to clean and replace the hydraulic filters periodically. Also, ensuring that hydraulic hoses are not cracked or brittle will help prevent leaks.
   
3. Track and Undercarriage Care: Regularly inspect the tracks and undercarriage for any signs of damage or excessive wear. Track tension should be checked frequently, and damaged or worn parts should be replaced. Lubrication of rollers and sprockets is essential to avoid wear and improve overall efficiency.
   
4. Cooling System: The cooling system plays a vital role in maintaining optimal engine temperature. Regularly check the radiator and coolant levels. It’s also important to clean the cooling fins to prevent overheating during extended use.
   
5. Periodic Inspections: Besides regular maintenance, periodic inspections by qualified technicians can help detect any issues early on. They can identify any signs of mechanical stress or damage that might not be immediately visible to the operator.
   

History and Success of Hitachi Excavators
Hitachi Construction Machinery, the manufacturer of the EX 120, has a rich history of providing high-quality equipment to the construction and mining industries. Founded in 1970 as part of the Hitachi Group, the company has become a global leader in manufacturing excavators and other heavy machinery. The EX series, introduced in the early 2000s, became highly successful due to its balance of power, efficiency, and reliability.
Hitachi excavators, including the EX 120, have become a preferred choice for contractors and equipment rental companies. The EX 120’s combination of strong performance, ease of use, and low operational costs has made it a top choice for small to medium-sized construction projects, from urban building sites to excavation in agricultural land.
Conclusion
The Hitachi EX 120 remains a popular choice in the world of hydraulic excavators, thanks to its efficient performance, advanced hydraulic systems, and strong digging capabilities. With proper care and regular maintenance, this machine can provide reliable service for many years. While it is susceptible to some common issues such as hydraulic leaks and undercarriage wear, these can be mitigated through proactive maintenance. For construction companies and contractors seeking a versatile, cost-effective excavator for various tasks, the Hitachi EX 120 continues to be an excellent option.