Removing Bushings from a Komatsu PC35MR Excavator: Step-by-Step Guide

[MikePhua]

When it comes to maintaining and repairing heavy equipment like the Komatsu PC35MR mini excavator, one common task that many operators and mechanics face is replacing worn or damaged bushings. Bushings play an essential role in reducing friction between moving parts and providing support to the components they connect. Over time, these bushings wear down, leading to increased friction, noise, and eventually equipment failure. When bushings become damaged, it’s crucial to remove and replace them in a timely manner to avoid further damage to the machine.
In this article, we’ll explore the methods and tools involved in removing bushings from a Komatsu PC35MR, as well as provide tips and tricks for making the job easier and more efficient.
Understanding the Role of Bushings in the Komatsu PC35MR
Bushings are small but vital components in machinery like the Komatsu PC35MR excavator. They are designed to reduce friction between metal parts, absorb shocks, and extend the lifespan of key moving components such as the pins, arms, and joints. In the case of the PC35MR, bushings are commonly found in areas like the bucket pins, arm joints, and booms. If a bushing becomes worn, it can cause excessive wear on other parts, like the pins or bushings themselves, leading to costly repairs down the line.
As part of regular maintenance, it’s important to inspect bushings regularly and replace them when signs of wear or damage are present. Removing and replacing bushings can be a difficult task, especially if the bushings are corroded, seized, or pressed into tight spaces. This is where knowledge of the proper tools and techniques becomes essential.
Common Challenges in Removing Bushings
When removing bushings from a Komatsu PC35MR or similar equipment, several challenges may arise:

1. Corrosion and Rust
   Over time, bushings can become rusted or corroded, making them difficult to remove. The build-up of rust can create a tight bond between the bushing and its housing, requiring extra force or specialized tools to break it loose.
   
2. Seized Bushings
   If the bushing has been in place for an extended period without lubrication, it can become seized to the metal housing or pin. This can make removal extremely difficult, requiring heating or even cutting the bushing out in some cases.
   
3. Limited Space
   The compact size of the Komatsu PC35MR mini excavator often means that there is limited space to work with, especially in tight areas like the arm joints or between the boom and the undercarriage. This requires creative solutions and compact tools to access and remove the bushings.
   
4. Damage to Surrounding Components
   During bushing removal, it’s important to avoid damaging surrounding components like the pins, arms, or housing. Using excessive force or incorrect methods can cause irreversible damage to these parts, leading to costly repairs.
   

Tools and Equipment for Bushing Removal
Before beginning the removal process, it’s essential to gather the right tools. Here are some of the most commonly used tools for removing bushings from a Komatsu PC35MR:

1. Hydraulic Press
   A hydraulic press is one of the most effective tools for removing bushings. It provides consistent force and can push the bushing out of the housing without damaging the surrounding components. A press with a high enough tonnage to handle the job is essential.
   
2. Bushing Driver Kit
   A bushing driver kit typically includes a set of tools designed to push or pull bushings out of their housings. The kit may include different sizes and types of drivers, including punches, pins, and sleeves, to suit various bushing sizes.
   
3. Heat Gun or Torch
   If a bushing is seized due to rust or corrosion, applying heat can help break the bond between the bushing and its housing. A heat gun or torch can be used to heat the area, making the removal process easier. However, care must be taken not to overheat or damage surrounding components.
   
4. Pneumatic Hammer or Impact Wrench
   In some cases, a pneumatic hammer or impact wrench may be used to break loose stubborn bushings. This method should be used cautiously, as excessive force can cause damage to surrounding parts.
   
5. Pullers and Extractors
   In some instances, using a puller or extractor can be an effective method for removing bushings. These tools grip the outside of the bushing and use mechanical force to pull it out of the housing.
   
6. Lubricants and Penetrating Oils
   Lubricants like WD-40 or penetrating oils can be applied to help loosen rust or seized bushings. These oils can penetrate small gaps and break the bond between the bushing and the metal, making removal easier.
   

Step-by-Step Process for Removing Bushings from the Komatsu PC35MR
The process of removing bushings from the Komatsu PC35MR will vary slightly depending on the exact location of the bushing and the type of equipment you’re working with. However, the general steps for removal are as follows:

1. Prepare the Work Area
   Ensure the machine is parked on level ground, and the engine is turned off. Use safety precautions such as gloves, eye protection, and work boots. Block the tracks and secure the excavator to ensure it doesn’t move during the repair process.
   
2. Remove Any Obstructions
   Depending on the bushing location, remove any components that obstruct access to the bushing. For example, you may need to remove pins, arms, or the bucket before accessing the bushing. This is especially true for bushings located within tight joint areas.
   
3. Inspect the Bushing
   Before starting the removal process, inspect the bushing for any signs of wear, rust, or corrosion. If the bushing is severely damaged, you may need to replace it entirely rather than attempting to remove it.
   
4. Apply Penetrating Oil
   If the bushing appears to be stuck, apply a generous amount of penetrating oil or lubricant to the area. Let the oil sit for 10-15 minutes to allow it to break down any rust or corrosion.
   
5. Heat the Bushing (If Necessary)
   For seized bushings, use a heat gun or torch to heat the surrounding area. Apply heat evenly and allow it to expand, which will help break the bond between the bushing and the housing. Be careful not to overheat the area or cause damage to the surrounding components.
   
6. Use the Hydraulic Press or Bushing Driver Kit
   If the bushing is still stuck, use a hydraulic press to apply steady pressure. If you don’t have access to a press, a bushing driver kit with the appropriate size driver can be used to push the bushing out of its housing. Apply even pressure to avoid damaging surrounding parts.
   
7. Check for Any Remaining Pieces
   After removing the bushing, inspect the area for any remaining pieces of the old bushing. Clean out any debris or fragments before installing a new bushing.
   
8. Install the New Bushing
   To install the new bushing, use a bushing driver to press the new bushing into place. Ensure it’s aligned properly before applying pressure. If necessary, lubricate the bushing to ease installation.
   

Additional Tips and Considerations

• Use the Right Tools: Always use the correct tools for the job. Using makeshift tools or incorrect sizes can cause damage to both the bushing and the equipment.
  
• Take Precautions with Heat: Be cautious when using heat to remove a bushing, as excessive heat can cause damage to seals, gaskets, and other components. Always heat the area slowly and evenly.
  
• Consider Professional Help: If the bushing removal process becomes too complex or if specialized tools are not available, consider seeking professional help. Many equipment repair shops can provide the necessary tools and expertise to complete the job efficiently.
  

Conclusion
Removing bushings from a Komatsu PC35MR mini excavator requires patience, precision, and the right tools. Whether you’re dealing with corrosion, seized parts, or limited access, following a step-by-step process and using the appropriate equipment can make the task much easier. Regular maintenance and timely bushing replacement are essential to keeping your excavator running smoothly and avoiding costly repairs in the future. By understanding the proper techniques and troubleshooting common issues, you can keep your Komatsu PC35MR in top condition for years to come.