Understanding and Troubleshooting Speed Sensor Issues in Komatsu 700H Dozers

[MikePhua]

   


Introduction
The Komatsu 700H series dozers are renowned for their robust performance in heavy-duty applications. However, like any complex machinery, they are susceptible to specific component failures. One such critical component is the speed sensor, which plays a pivotal role in the dozer's operation. Understanding its function, common issues, and troubleshooting methods is essential for maintaining optimal performance.
Function of the Speed Sensor
The speed sensor in the Komatsu 700H dozer monitors the rotational speed of the tracks. This data is crucial for the machine's control system to adjust hydraulic pressures, manage travel speeds, and ensure smooth operation. A malfunctioning speed sensor can lead to erratic behavior, such as unintended jerking or uneven tracking.
Common Symptoms of Speed Sensor Failure
Operators may notice several signs indicative of a failing speed sensor:

• Unintended Jerking: The dozer may lurch forward or to the side without input from the operator.
  
• Uneven Tracking: One track may move faster than the other, causing the dozer to veer off course.
  
• Error Codes: Diagnostic systems may display fault codes related to speed sensor malfunctions.
  

For instance, a user reported that their late serial number 700H exhibited jerking to the left without any operator input, both while pushing and traveling. This behavior was suspected to be a symptom of a speed sensor failure.
Troubleshooting Speed Sensor Issues
To diagnose and address speed sensor problems:

1. Visual Inspection: Check for any visible damage to the sensor or its wiring.
   
2. Electrical Testing: Using a multimeter, measure the sensor's output voltage. Refer to the machine's service manual for the expected voltage range.
   
3. Sensor Replacement: If the sensor is faulty, replace it with an OEM part to ensure compatibility and reliability.
   

Preventive Maintenance Tips
To prolong the life of the speed sensor and other critical components:

• Regular Cleaning: Keep the sensor and surrounding areas free from dirt and debris.
  
• Routine Inspections: Conduct regular checks of the sensor's wiring and connections.
  
• Use OEM Parts: Always replace faulty sensors with original equipment manufacturer parts to maintain system integrity.
  

Conclusion
The speed sensor is integral to the Komatsu 700H dozer's performance. Understanding its function and being aware of potential issues can help operators maintain smooth and efficient operation. Regular maintenance and prompt attention to any symptoms of failure will ensure the longevity and reliability of the machine.