Komatsu 700H Dozer: An Overview of Performance, Issues, and Maintenance

[MikePhua]

The Komatsu 700H is a robust, mid-sized track dozer known for its power and reliability in various construction, mining, and landscaping projects. Designed with a focus on ease of operation and long-term durability, the 700H has become a staple in many heavy equipment fleets worldwide. However, like all heavy machinery, it is not without its issues, especially concerning its hydraulics, transmission, and undercarriage components.
This article delves into the key features, common problems, maintenance tips, and troubleshooting techniques for the Komatsu 700H dozer. With proper understanding and care, operators can extend the life of their machine while avoiding costly downtime.
Overview of the Komatsu 700H Dozer
The Komatsu 700H is part of the H-series track dozers, a line of machines designed to offer superior traction, engine power, and operator comfort. The dozer’s engine typically offers between 130 to 160 horsepower, depending on the specific configuration, making it suitable for medium to heavy-duty tasks such as grading, pushing earth, and clearing obstacles. The 700H is widely used for projects that require high performance and minimal maintenance, including road construction, mining, and land clearing.
Key Features:

1. Powerful Engine: The Komatsu 700H typically comes with a 6-cylinder diesel engine. This engine is known for its fuel efficiency and ability to deliver consistent power over long periods, making it suitable for demanding tasks.
   
2. Hydraulic System: The dozer is equipped with a hydraulic system designed to provide smooth and powerful blade operations, including lifting, tilting, and angling of the dozer blade.
   
3. Track System: The 700H features an advanced track system, allowing for excellent ground contact and traction. This system is particularly useful for operations in difficult terrain and soft soils.
   
4. Operator Comfort: The dozer’s cabin is designed for optimal visibility and ease of operation. The controls are ergonomically arranged to reduce operator fatigue and enhance productivity.
   

Common Issues with the Komatsu 700H Dozer
While the 700H is generally regarded as a reliable machine, operators have reported several recurring issues related to its components. Understanding these problems can help owners and operators address them before they lead to more significant complications.

1. Hydraulic System Failures: One of the most common issues with the 700H dozer is related to its hydraulic system. Hydraulic leaks, weak hydraulic pressure, and sluggish blade movement are often signs of a problem. These issues can be caused by:
   • Worn seals or hoses
     
   • Clogged hydraulic filters
     
   • Contaminated hydraulic fluid
     
   • Malfunctioning pumps or valves
     
   Regular maintenance of the hydraulic system is crucial, including checking for leaks, replacing filters, and ensuring fluid cleanliness.
   
2. Transmission Problems: Some operators report issues with the transmission, especially with the forward/reverse gear function becoming erratic. Common symptoms of transmission problems include:
   • Delayed or rough shifting
     
   • Inability to engage certain gears
     
   • Slipping in high gears
     
   Transmission problems may be attributed to worn or damaged transmission bands, low fluid levels, or malfunctioning control valves.
   
3. Undercarriage Wear: As with many heavy-duty track machines, the undercarriage of the Komatsu 700H can experience wear and tear over time. Issues such as track sag, damaged rollers, and worn sprockets are common. The undercarriage is a critical part of the machine as it supports the weight and facilitates movement.
   Regularly inspecting the tracks, rollers, and sprockets is essential for ensuring that the dozer operates smoothly. Replacing worn components on time can prevent more costly damage to the machine’s undercarriage.
   
4. Electrical System Failures: Electrical problems, though less frequent, can still occur, especially with older models. Issues can range from faulty sensors to problems with the battery charging system. A common sign of electrical failure is inconsistent operation of electronic components such as the blade tilt controls or engine monitoring systems.
   
5. Engine Overheating: The Komatsu 700H’s engine may overheat under certain conditions, particularly during extended operation in hot weather or when operating in heavy-duty environments. Overheating can result in:
   • Coolant system blockages
     
   • Faulty thermostats
     
   • Worn water pumps
     
   Regularly monitoring coolant levels, maintaining the radiator, and ensuring that the engine cooling system is functioning properly can help prevent overheating.
   

Troubleshooting and Solutions
Given the variety of issues that can arise with the Komatsu 700H, it’s essential for operators to have a clear understanding of how to troubleshoot common problems. Here are some solutions to address the most frequent issues:

1. Hydraulic System Troubleshooting:
   • Check for Leaks: Inspect hoses, seals, and valves for any signs of leakage. Leaks can be easily detected by looking for puddles or oil stains beneath the machine.
     
   • Change the Hydraulic Fluid: If the fluid is contaminated or discolored, replace it with the recommended type. Clean hydraulic fluid ensures that the system operates at optimal pressure.
     
   • Inspect Filters: Replace clogged or dirty hydraulic filters to ensure proper flow and pressure throughout the system.
     
   • Pump and Valve Inspection: If the system remains sluggish despite fluid changes, the hydraulic pump or valves may need to be inspected or replaced.
     
2. Transmission Issues:
   • Check Fluid Levels: Low transmission fluid can cause erratic shifting. Ensure that fluid levels are within the recommended range and add fluid if necessary.
     
   • Inspect the Transmission Bands: Worn or damaged bands can lead to slipping. Replacing these bands can often resolve shifting issues.
     
   • Consult the Manual: If the transmission continues to fail, it may require more advanced repair, such as valve servicing or internal gear inspections.
     
3. Undercarriage Maintenance:
   • Track Tensioning: Regularly check the track tension to ensure it is properly adjusted. Loose tracks can cause excessive wear, while overly tight tracks can stress the undercarriage.
     
   • Roller and Sprocket Inspection: Inspect the rollers and sprockets for wear or damage. Replace worn components immediately to prevent further issues.
     
   • Lubrication: Ensure that the undercarriage components are properly lubricated to reduce friction and prolong their lifespan.
     
4. Electrical System Repairs:
   • Check Battery Voltage: Use a voltmeter to check the battery’s charge and ensure it is functioning correctly. A weak or dead battery should be replaced.
     
   • Inspect Wiring: Look for any loose or corroded wiring connections, particularly around the electrical components and sensors. Cleaning and tightening connections can resolve many electrical issues.
     
5. Preventing Engine Overheating:
   • Regular Coolant Checks: Ensure that the coolant levels are topped up and that there are no leaks in the cooling system.
     
   • Radiator Cleaning: Periodically clean the radiator to remove any dirt or debris that may impede airflow, particularly in dusty environments.
     
   • Thermostat and Pump Inspections: If the engine continues to overheat, check the thermostat and water pump for faults.
     

Maintenance Tips for the Komatsu 700H
Maintaining the Komatsu 700H on a regular basis will significantly extend the lifespan of the machine and reduce the likelihood of costly repairs. Here are some general maintenance tips:

1. Scheduled Oil Changes: Regularly change the engine oil and hydraulic fluid as per the manufacturer's recommendations. This helps prevent wear and tear and ensures the system operates smoothly.
   
2. Inspect and Replace Filters: Check the air and fuel filters regularly and replace them when needed. Dirty filters can cause engine performance issues and fuel inefficiency.
   
3. Track and Undercarriage Maintenance: Keep the tracks in proper tension and regularly inspect the undercarriage components for wear. Replace any damaged parts promptly to avoid further issues.
   
4. Lubrication: Ensure that all moving parts are properly lubricated. This includes the blade controls, hydraulic pumps, and undercarriage components.
   
5. Electrical System Checks: Periodically inspect the electrical system, including the battery and wiring, to ensure everything is functioning correctly.
   

Conclusion
The Komatsu 700H dozer is a powerful and versatile piece of equipment used in a wide variety of heavy-duty tasks. While it is a reliable machine, operators must be vigilant in maintaining the dozer and addressing common issues such as hydraulic failures, transmission problems, and undercarriage wear. Regular inspection, prompt troubleshooting, and following manufacturer-recommended maintenance schedules are key to ensuring that the 700H continues to perform at its best throughout its lifecycle. With proper care, the Komatsu 700H can provide many years of productive service.