Hitachi EX45 Final Drive New Floating Seal Leak: Troubleshooting and Solutions

[MikePhua]

The Hitachi EX45 is a reliable and durable compact excavator, widely used in construction and excavation projects. However, like any piece of heavy equipment, it can experience wear and tear over time. One of the common issues that operators face is a floating seal leak in the final drive. This issue can lead to a loss of hydraulic fluid, which affects the performance of the final drive and may result in costly repairs if not addressed quickly. This article will cover the causes, troubleshooting, and solutions for dealing with a floating seal leak in the Hitachi EX45 final drive.
Understanding the Floating Seal in the Final Drive
The final drive in an excavator is a critical component that transfers power from the engine to the tracks. It typically includes a motor, gears, and a seal system designed to keep the hydraulic fluid contained and prevent contamination. The floating seal is a key part of this system and helps maintain pressure by sealing the interface between the motor and the final drive housing.
If the floating seal begins to leak, hydraulic fluid may escape, causing a decrease in the performance of the final drive and potential damage to the internal components. This can lead to costly repairs if left unresolved.
Common Symptoms of a Floating Seal Leak
When a floating seal starts to leak, you may notice several symptoms that indicate a problem with the final drive. These include:

1. Hydraulic Fluid Loss: One of the most obvious signs of a leaking floating seal is a noticeable drop in hydraulic fluid levels. If the leak is significant, you may see puddles of hydraulic fluid around the final drive.
   
2. Increased Noise: A failing floating seal can cause a whining or grinding noise coming from the final drive. This noise is often a result of reduced lubrication and pressure within the final drive components.
   
3. Poor Performance: If the final drive is leaking hydraulic fluid, you may experience reduced power or slow movement in the excavator’s tracks. The final drive may struggle to maintain the same level of performance, especially under heavy load conditions.
   
4. Excessive Heat: A leaking floating seal can cause a buildup of heat within the final drive as the lubrication becomes insufficient to properly cool the system. This can lead to overheating, which can further damage the internal components.
   

Causes of Floating Seal Leaks in the Hitachi EX45
Several factors can contribute to a floating seal leak in the final drive of the Hitachi EX45. Some of the most common causes include:

1. Worn or Damaged Seal: Over time, the floating seal can wear out due to exposure to constant pressure and heat. The seal may become brittle or cracked, allowing hydraulic fluid to escape.
   
2. Contamination: Dirt, debris, and other contaminants can enter the final drive if the seal becomes damaged or improperly installed. These contaminants can damage the seal and cause it to fail prematurely.
   
3. Improper Installation: If the floating seal is not installed correctly during maintenance or repair, it may not form a proper seal, leading to leaks. Additionally, using the wrong type of seal for the specific final drive model can also cause issues.
   
4. Excessive Pressure: If the hydraulic system is operating at higher-than-normal pressure, it can put extra stress on the floating seal, leading to leaks. This can occur due to faulty hydraulic components or improper settings.
   

Troubleshooting the Floating Seal Leak
If you suspect that the floating seal in your Hitachi EX45 final drive is leaking, it’s important to perform a thorough inspection to confirm the issue. Here are the steps to troubleshoot the leak:

1. Check the Hydraulic Fluid Levels: Start by inspecting the hydraulic fluid levels in the system. If the levels are low, it’s a strong indication that there is a leak somewhere in the final drive. Look for signs of fluid leakage around the final drive housing.
   
2. Inspect the Seal Area: Visually inspect the area around the floating seal for any signs of hydraulic fluid leakage. If you see fluid coming from the seal area, it’s likely that the floating seal is damaged or worn out.
   
3. Check for Contamination: Examine the final drive for any signs of dirt or debris that may have entered the system. Contamination can damage the floating seal and cause it to fail. If necessary, clean the area around the seal to prevent further contamination.
   
4. Listen for Unusual Noises: Start the excavator and listen for any unusual noises, such as whining or grinding, coming from the final drive. These sounds can indicate that the floating seal is failing and that the internal components are not properly lubricated.
   
5. Inspect the Hydraulic Pressure: If possible, check the hydraulic pressure in the system to ensure it is within the manufacturer’s recommended range. Excessive pressure can put additional stress on the floating seal and lead to leaks.
   

Solutions and Repair Options
Once you’ve identified that the floating seal is the cause of the leak, there are several repair options available:

1. Replace the Floating Seal: The most effective solution to a leaking floating seal is to replace it with a new one. Make sure to use the correct part that is compatible with your Hitachi EX45 model. During replacement, ensure that the seal is installed correctly to prevent future leaks.
   
2. Clean the Final Drive: Before installing a new floating seal, thoroughly clean the final drive housing and surrounding components. This will help prevent contamination and ensure the new seal can create a proper seal.
   
3. Check for Other Damage: While replacing the floating seal, inspect the internal components of the final drive for any signs of damage or wear. If any other components are damaged, they may need to be repaired or replaced to prevent future issues.
   
4. Preventive Maintenance: To avoid future floating seal leaks, perform regular maintenance on the final drive. This includes checking the hydraulic fluid levels, inspecting the seals, and cleaning the system to prevent contamination.
   

Conclusion
A floating seal leak in the Hitachi EX45 final drive can lead to significant performance issues and potential damage if not addressed promptly. By understanding the common symptoms, causes, and troubleshooting steps, operators can quickly diagnose and resolve the problem. Replacing the faulty seal and performing regular maintenance can help extend the life of the final drive and keep the excavator running smoothly. Regular inspection and care are crucial for ensuring the longevity of the machine and preventing costly repairs in the future.