Restoring the CAT 955K: A Winter Project Worth Taking On

[MikePhua]

Introduction to the CAT 955K Dozer
The Caterpillar 955K dozer is one of the classic pieces of equipment that has stood the test of time. Launched in the 1960s, the 955K is renowned for its versatility and reliability in various construction and agricultural applications. With a durable undercarriage, a powerful engine, and the ability to work in harsh environments, it was a favorite among operators who needed a machine that could handle tough conditions.
Despite being an older model, the CAT 955K still holds value for those who need a solid piece of machinery. Many of these dozers have been out of service for years but are still capable of performing efficiently if restored properly. This article will explore the steps, challenges, and rewards involved in restoring a CAT 955K, as well as the types of modifications and upgrades that can be made to enhance its performance.
The Appeal of a Winter Project
For many operators and heavy equipment enthusiasts, restoring a classic machine like the CAT 955K is not only a practical task but a rewarding hobby. The winter season, with its colder weather and reduced work schedules, presents the perfect opportunity for tackling such projects. During this downtime, operators can focus on mechanical repairs, component replacements, and system upgrades that would be difficult to address during the busy working months.
Restoring an older machine like the 955K can be a cost-effective way to extend its life and improve performance without the expense of purchasing a new piece of equipment. It also allows operators to become more familiar with their machines, which can lead to more efficient maintenance in the future.
Steps to Restoring the CAT 955K
Restoring a classic dozer like the CAT 955K involves multiple steps, each addressing a different part of the machine. Here are the key areas to focus on when embarking on a restoration project:

1. Assessment and Planning
   The first step in restoring any heavy equipment is conducting a thorough assessment. This involves checking the condition of critical components such as the engine, transmission, hydraulic systems, undercarriage, and electrical systems. It's important to identify any worn or damaged parts that need replacement and determine if any upgrades are necessary.
   • Engine: Check for signs of oil leaks, worn gaskets, or weak compression. If the engine has been sitting idle for years, it may require a full rebuild or at least a major tune-up.
     
   • Hydraulic System: Inspect the hydraulic pump, hoses, cylinders, and valve blocks. Leaks in the hydraulic system can reduce efficiency and cause costly damage.
     
   • Undercarriage: Examine the tracks, rollers, and sprockets. If they are worn down, replacing or repairing them will be necessary for optimal performance.
     
   • Transmission and Final Drives: Inspect the transmission fluid and check for any slipping or unusual noises that could indicate an issue with the transmission or final drives.
     
2. Engine Overhaul
   For machines like the CAT 955K, the engine is often the most critical component. A complete overhaul may be necessary if the engine shows significant wear. During the winter project, the engine should be disassembled, inspected, and rebuilt if necessary.
   • Cylinder Head and Block: Ensure there are no cracks or warping. A cracked block will require replacement, while a warped cylinder head might need resurfacing.
     
   • Pistons and Rings: Over time, pistons and rings wear down, which can reduce engine efficiency. Replacing these components can restore the engine’s power and prevent oil contamination.
     
   • Fuel System: Clean or replace the fuel injectors, fuel lines, and fuel filters. Clogged fuel systems can reduce engine performance.
     
3. Hydraulic System Refurbishment
   The hydraulic system is crucial for the dozer's ability to lift and push heavy loads. Leaks and worn seals are common issues in older machines. During the restoration process, the hydraulic pump and cylinders should be checked for wear.
   • Pump and Valves: The pump is the heart of the hydraulic system. If it’s worn, it should be replaced with a high-quality, compatible pump.
     
   • Seals and O-rings: Replacing the seals and O-rings throughout the hydraulic system will prevent leaks and ensure consistent performance.
     
   • Hydraulic Fluid: Always replace the hydraulic fluid during restoration to ensure the system runs smoothly.
     
4. Undercarriage Replacement or Repair
   A worn-out undercarriage can dramatically affect the performance of the 955K. The undercarriage absorbs most of the wear and tear from rough terrain, so regular maintenance and replacement of certain parts are necessary.
   • Tracks: If the tracks are excessively worn, they should be replaced. Tracks are essential for providing traction and stability, especially in challenging work environments.
     
   • Rollers and Sprockets: Check for signs of wear on the rollers and sprockets. These components work together to keep the machine’s tracks in proper alignment.
     
   • Idlers: Idlers help maintain proper tension on the tracks. If they are worn, it could result in poor track performance.
     
5. Electrical System Upgrades
   Older equipment like the CAT 955K may have outdated electrical systems. Rewiring or upgrading the electrical components can help ensure reliability and reduce the risk of electrical failures on the job site.
   • Wiring Harness: Replace old or corroded wiring to prevent electrical shorts.
     
   • Alternator and Battery: Ensure the alternator is functioning correctly, and replace the battery if necessary. A weak battery can cause starting issues.
     
   • Lighting System: Upgrading to LED lights not only improves visibility but also increases energy efficiency.
     
6. Cab and Operator Comfort
   The operator's cab is where most of the work happens, so ensuring comfort and visibility is key to a successful restoration. Some upgrades may include:
   • Seat Replacement: Replace worn-out seats with more ergonomic options.
     
   • Air Conditioning and Heating: Installing or upgrading the HVAC system can make a huge difference in operator comfort, especially in extreme weather conditions.
     
   • Control Systems: Updating the control systems for improved ease of use and responsiveness can make the machine more operator-friendly.
     
7. Testing and Calibration
   After all the work has been completed, it's essential to thoroughly test the dozer. Check the engine, hydraulics, and undercarriage to ensure everything is functioning properly. Running the machine through a series of tests will help identify any lingering issues that need attention before putting it back into full service.
   

Challenges of Restoring the CAT 955K
Restoring a classic dozer like the 955K comes with its challenges. Some of the issues operators may face include:

• Availability of Parts: Since the 955K is an older model, finding replacement parts can be difficult. Operators often rely on aftermarket suppliers or used parts, which may not always be in the best condition.
  
• Time and Labor-Intensive Work: A full restoration project requires a significant amount of time and effort. It’s important to be prepared for the amount of work that goes into refurbishing an older machine.
  
• Cost: While restoring a machine is often more cost-effective than purchasing a new one, it still requires a substantial investment in parts, labor, and tools.
  

Conclusion: The Rewards of Restoration
Undertaking a winter project like restoring a CAT 955K dozer is not for the faint of heart, but it can be incredibly rewarding. Not only does it breathe new life into an older machine, but it also provides a sense of accomplishment knowing that you’ve extended its service life for years to come. The project requires a thorough understanding of the equipment, access to quality parts, and a good amount of mechanical skill. However, for those who take on the challenge, the result is a powerful, reliable dozer ready to tackle any job, even in the harshest conditions.
By restoring a classic like the 955K, operators not only honor a piece of heavy equipment history but also create a valuable tool that will continue to serve them for many years.