Dealing with Water Trapped in the Turntable of a PC60 Excavator: Causes, Solutions, and Preventative Measures

[MikePhua]

Excavators, like the Komatsu PC60, are designed to withstand heavy work in tough conditions. However, one issue that can arise over time is water getting trapped in the turntable, which can lead to a series of mechanical problems if not addressed properly. This article delves into the common causes of water accumulation in the turntable of an excavator, explains the risks associated with this issue, and provides step-by-step guidance on how to deal with it.
Understanding the Turntable and Its Importance
The turntable, also known as the upper structure or swing mechanism, is a vital part of any tracked excavator. It allows the upper part of the machine, including the cabin, boom, arm, and bucket, to rotate 360 degrees, giving the operator full range of motion. This rotation is powered by hydraulic motors and supported by bearings and seals that ensure smooth and effective movement.
Water entering the turntable can disrupt the hydraulic systems, cause rust and corrosion, and reduce the overall lifespan of the machine. It's critical to maintain a dry and clean turntable to avoid costly repairs and downtime.
Common Causes of Water Trapping in the Turntable
There are several reasons why water may become trapped in the turntable of the Komatsu PC60 or similar machines:

1. Damaged Seals and Gaskets: The turntable is sealed to prevent water and debris from entering, but over time, seals and gaskets can degrade. If seals are cracked, worn, or improperly fitted, they may allow water to seep into the housing where the hydraulic motors and gears are located.
   
2. Heavy Rain and Wet Working Conditions: Excavators working in wet or muddy conditions are more likely to accumulate water. If the machine is working in areas with heavy rainfall or working near bodies of water, the turntable may collect water through the unsealed gaps or vents.
   
3. Improper Maintenance or Cleaning: Failing to perform regular maintenance or clean the excavator properly can allow water to accumulate unnoticed. For example, neglecting to drain water that has entered the turntable after a cleaning or washing session can lead to buildup.
   
4. Condensation: In colder climates, condensation can form inside the turntable as the temperature fluctuates. This is especially common when an excavator is stored in an environment with significant temperature changes, such as a garage or storage facility.
   
5. Faulty Drainage System: Excavators like the Komatsu PC60 typically have a drainage system to help remove water and prevent it from accumulating. If this drainage system is clogged or damaged, it can lead to water pooling inside the turntable.
   

The Risks of Water in the Turntable
Water trapped in the turntable can lead to a number of mechanical issues if left untreated:

1. Corrosion and Rusting: Water can cause the internal components of the turntable to rust, including bearings, gears, and hydraulic motors. Over time, this can severely affect the functionality of the turntable, causing slow or jerky rotation, decreased power, and even complete mechanical failure.
   
2. Hydraulic Fluid Contamination: Water can mix with hydraulic fluid, leading to contamination. This can degrade the performance of the hydraulic system, causing seals to fail and resulting in reduced efficiency or damage to other hydraulic components.
   
3. Premature Wear and Tear: Continuous exposure to water can accelerate wear on the mechanical components inside the turntable. The added moisture can cause friction and strain, leading to a reduction in the lifespan of critical parts such as the swing bearing and gears.
   
4. Operational Downtime: If water accumulation leads to mechanical failure or hydraulic issues, it can cause the excavator to stop working altogether, resulting in costly repairs and downtime. This can significantly impact a project’s timeline and budget.
   

How to Identify Water Trapped in the Turntable
Before you can address the problem of water in the turntable, you need to know how to identify it. Here are some signs that water may be trapped in your excavator’s turntable:

1. Unusual Sounds: If you hear grinding or squeaking noises from the swing mechanism, it could be a sign that water has caused corrosion or rust on the turntable’s moving parts.
   
2. Erratic Swinging Movement: If the turntable's rotation becomes slow, jerky, or less responsive, water contamination or buildup may be affecting the hydraulic system.
   
3. Visible Rust: If you notice rust spots around the turntable or hydraulic components, water may have entered the area and begun causing corrosion.
   
4. Leaking Hydraulic Fluid: Water in the turntable can cause seals to fail, resulting in hydraulic fluid leaks. If you notice hydraulic fluid pooling around the base of the swing mechanism, it could indicate that water is present.
   

Steps to Remove Water from the Turntable
If you suspect that water has accumulated in the turntable of your Komatsu PC60, here are the steps you should follow to remove it:

1. Shut Down the Machine: Before performing any maintenance, ensure that the excavator is turned off and securely parked.
   
2. Inspect the Drain Plug: Most excavators are equipped with a drain plug located at the lowest point of the turntable. This allows water to drain out. Check for any visible water or moisture around the drain plug, and use a wrench to remove it carefully.
   
3. Drain the Water: Once the drain plug is removed, allow the water to drain completely. You may need to tilt the turntable slightly to ensure all water is released.
   
4. Flush the System: If there’s any suspicion that water has contaminated the hydraulic fluid or other parts of the turntable, it’s a good idea to flush the system with fresh hydraulic oil. This helps clear any residual water and contaminants that may have accumulated in the bearings or gears.
   
5. Inspect Seals and Gaskets: Check the seals and gaskets around the turntable for any signs of wear or damage. Replace any faulty seals to prevent future water intrusion.
   
6. Clean the Area: After draining the water, clean the area around the turntable thoroughly to remove any dirt, debris, or corrosion that may have been caused by the water.
   
7. Reassemble and Test: Once you’ve removed the water, replaced any damaged seals, and cleaned the turntable, reassemble everything and test the turntable’s operation. Check for any irregularities in movement or unusual sounds.
   

Preventing Water Accumulation in the Future
To avoid the problem of water accumulation in the turntable, consider the following preventive measures:

1. Regular Maintenance: Perform regular inspections of the turntable seals, gaskets, and drainage system. Ensure that the turntable is properly sealed and that there are no gaps where water can enter.
   
2. Proper Storage: Store the excavator in a dry, climate-controlled environment to reduce the risk of condensation forming inside the turntable.
   
3. Clean and Drain After Use: After each use, especially in wet conditions, clean the machine thoroughly and drain any accumulated water. Be sure to check the turntable for moisture before storing the machine.
   
4. Use High-Quality Seals: Invest in high-quality seals and gaskets that are resistant to wear and can better handle the demands of heavy-duty work.
   
5. Check Hydraulic Fluid Regularly: Monitor the hydraulic fluid for any signs of contamination. If water is detected in the fluid, perform a flush to prevent damage to the hydraulic components.
   

Real-World Example: Water Damage in the Turntable of a Komatsu PC60
In a recent project, a construction company working in a rainy region faced issues with water trapped in the turntable of their Komatsu PC60 excavator. Despite regular cleaning and maintenance, the excavator began exhibiting signs of slow movement and strange noises from the swing mechanism.
Upon inspection, the team discovered that water had accumulated in the turntable due to a damaged seal. The water had mixed with the hydraulic fluid, leading to contamination and causing the swing mechanism to fail. The team drained the water, replaced the seals, and flushed the hydraulic system. After the repair, the excavator returned to full functionality, preventing further downtime.
Conclusion: Ensuring Longevity with Proper Turntable Maintenance
Water trapped in the turntable of a Komatsu PC60 excavator can lead to a range of issues, from corrosion and hydraulic contamination to operational failure. By understanding the causes of water accumulation and taking the necessary steps to remove it, you can protect your equipment and ensure its longevity. Regular maintenance, proper storage, and timely repairs are essential for keeping your excavator running smoothly and avoiding costly repairs in the future.