International TD25 Track Tensioner Leaking: Diagnosis and Repair

[MikePhua]

Introduction
The International TD25, a robust crawler tractor introduced in the mid-20th century, has been a staple in heavy-duty applications such as construction and mining. However, like many vintage machines, it is prone to certain mechanical issues over time. One common problem faced by operators is the leaking of the track tensioner, which can lead to track slack and reduced machine efficiency.
Understanding the Track Tensioner System
The track tensioner on the TD25 is a hydraulic mechanism designed to maintain proper track tension, ensuring optimal performance and longevity of the undercarriage. It consists of a cylinder, piston, and seals that work together to adjust and maintain the desired tension. When these components wear out or become damaged, grease can leak, leading to a loss of tension and potential track derailment.
Common Causes of Leaks

1. Worn or Damaged Seals: Over time, the seals within the tensioner can degrade due to constant pressure and exposure to contaminants.
   
2. Pitted or Scored Cylinder Walls: If the cylinder walls become damaged, they can cause the seals to wear unevenly, leading to leaks.
   
3. Improper Assembly or Installation: Incorrect installation of components or using incompatible parts can result in misalignment and subsequent leaks.
   

Diagnosis
To diagnose a leaking track tensioner on the TD25, operators should:

• Inspect the Track: Check for signs of slack or uneven wear, indicating a loss of tension.
  
• Examine the Grease Fitting: Look for any grease leakage around the zerk fitting, which could suggest a seal failure.
  
• Check for Grease Accumulation: Presence of grease around the tensioner area can confirm a leak.
  

Repair Procedure
Repairing a leaking track tensioner on the TD25 involves several steps:

1. Track Removal: Detach the track to gain access to the tensioner assembly.
   
2. Idler Removal: Remove the front idler to expose the tensioner cylinder.
   
3. Disassembly: Carefully disassemble the tensioner components, noting the order and orientation of parts.
   
4. Inspection: Examine the cylinder walls for any signs of damage or wear.
   
5. Seal Replacement: Install new seals and O-rings, ensuring they are compatible with the original specifications.
   
6. Reassembly: Reassemble the tensioner, applying appropriate torque to all fasteners.
   
7. Reinstallation: Reinstall the idler and track, ensuring proper alignment and tension.
   

Preventive Maintenance Tips
To prevent future leaks and extend the life of the track tensioner:

• Regular Inspections: Periodically check the tensioner for signs of wear or leakage.
  
• Use Quality Grease: Ensure the use of high-quality grease that meets the manufacturer's specifications.
  
• Proper Storage: Store the machine in a dry, clean environment to reduce exposure to contaminants.
  
• Timely Repairs: Address any issues promptly to prevent further damage to the tensioner and related components.
  

Conclusion
A leaking track tensioner on the International TD25 can significantly impact machine performance. By understanding the system's components, diagnosing the issue accurately, and performing timely repairs, operators can ensure the longevity and efficiency of their equipment. Regular maintenance and attention to detail are key to preventing such issues and maintaining optimal machine performance.