How to Effectively Remove Water from a Hydraulic System

[MikePhua]

Introduction: The Importance of Clean Hydraulic Fluid
Hydraulic systems play a critical role in the operation of heavy machinery, from construction equipment to industrial machines. These systems rely on hydraulic fluid to transfer power, reduce friction, and maintain optimal functioning. However, water contamination in hydraulic fluid is a common issue that can cause significant damage to the system. Water can enter the hydraulic fluid through various means, such as leaks, condensation, or exposure to moisture in the air.
When water enters a hydraulic system, it can lead to several problems, including corrosion, reduced lubrication, and impaired performance. For this reason, removing water from the hydraulic system is crucial to maintaining machine health and ensuring its long-term performance. In this article, we’ll explore how water can affect hydraulic systems, the best methods for removing water, and preventive measures to keep the system clean.
How Water Contaminates Hydraulic Fluid
Water can enter a hydraulic system in several ways:

1. Condensation: The temperature differences between the machine's internal components and the external environment can cause moisture to accumulate in the system.
   
2. Leaks: Seals and gaskets can deteriorate over time, allowing water to seep into the hydraulic system.
   
3. Flooding: Operating machinery in wet conditions, such as in rain, flooding, or high-humidity environments, can introduce water into the system.
   
4. Improper Storage: Hydraulic fluids that are not stored properly may absorb moisture from the air or be contaminated during handling.
   

Once water is in the system, it can cause oxidation, promote rust and corrosion on metal components, and degrade the viscosity of the hydraulic fluid. Over time, this can lead to pump failures, valve malfunctions, and even catastrophic breakdowns if not addressed promptly.
Symptoms of Water Contamination in Hydraulic Systems
Water contamination can manifest in various ways:

1. Foaming: The presence of water in hydraulic fluid can cause the fluid to foam, reducing its ability to lubricate and transfer power effectively.
   
2. Rust and Corrosion: Water can react with metal components inside the hydraulic system, causing rust or corrosion. This can weaken parts, leading to premature failure.
   
3. Decreased System Performance: Water contamination can cause the hydraulic system to operate less efficiently, leading to sluggish or inconsistent performance.
   
4. Increased Wear: Water can alter the fluid’s lubricating properties, causing increased friction and wear on pumps, valves, and seals.
   

Methods for Removing Water from a Hydraulic System

1. Drain and Replace the Hydraulic Fluid
   • Step 1: The most effective way to remove water from the hydraulic system is to completely drain the contaminated hydraulic fluid. Start by turning off the machine and placing it on a stable, level surface.
     
   • Step 2: Locate the drain plug or drain valve for the hydraulic system and remove the fluid. Be sure to dispose of the contaminated fluid according to local regulations.
     
   • Step 3: Replace the contaminated fluid with fresh, clean hydraulic oil that is free from water. Make sure to use the manufacturer-recommended fluid type to ensure optimal performance.
     
2. Flush the Hydraulic System
   • After draining the contaminated fluid, it’s advisable to flush the system to remove any residual water or debris.
     
   • Step 1: To do this, you may need to use a hydraulic fluid flush solution, which is designed to clean the internal components of the system.
     
   • Step 2: Run the machine for a short period, allowing the flush fluid to circulate through the system. This process will help remove any leftover water, dirt, and sludge.
     
   • Step 3: After the flushing is complete, drain the flush solution and replace it with fresh hydraulic fluid. This will ensure that the system is completely clean and free from water.
     
3. Use a Water-Absorbing Filter or Dehydrator
   • Step 1: In some cases, using a water-absorbing filter or dehydrator can help remove water without draining the system. These filters are designed to attract and absorb water from the hydraulic fluid.
     
   • Step 2: Install the filter in the return line or in the reservoir, depending on your system configuration. The filter will help pull water out of the fluid over time.
     
   • Step 3: Run the machine and monitor the filter regularly. Replace the filter as needed to continue removing moisture from the system.
     
4. Use a Vacuum or Centrifugal Separator
   • Vacuum: A vacuum pump can be used to draw moisture out of the hydraulic fluid. The pump is connected to the reservoir, and the vacuum system removes water, leaving the hydraulic fluid behind.
     
   • Centrifugal Separator: A centrifugal separator works by spinning the hydraulic fluid at high speeds, causing the water droplets to separate from the oil. The separated water is then removed, and the clean fluid remains in the system.
     

Preventive Measures to Avoid Water Contamination

1. Regular Fluid Monitoring
   • Regularly check the condition of the hydraulic fluid for signs of contamination. Testing the fluid for water content can help identify early signs of contamination and prevent further damage.
     
2. Check Seals and Gaskets
   • Ensure that all seals and gaskets are in good condition to prevent water from entering the hydraulic system. Replace any worn-out seals promptly to maintain a tight seal.
     
3. Proper Storage and Handling of Hydraulic Fluid
   • When storing hydraulic fluid, make sure it’s kept in a sealed container to avoid moisture absorption. Store the fluid in a dry area with minimal humidity.
     
4. Operate in Dry Conditions
   • If possible, avoid operating the equipment in wet or humid conditions. Water exposure can lead to faster contamination, especially during heavy rains or when working in swampy areas.
     
5. Maintain the Machine’s Hydraulic System
   • Perform regular maintenance on the hydraulic system, including cleaning the reservoir, checking the filters, and ensuring the system is operating efficiently. Regular maintenance helps prevent water buildup and ensures smooth operation.
     

Real-World Examples: Preventing Water Contamination in the Field
Operators in the field often face the challenge of water contamination in their hydraulic systems, especially in wet or high-humidity environments. A construction site in Oregon recently reported issues with hydraulic fluid contamination due to consistent rain during excavation work. The equipment’s performance suffered, and after investigating, the operator found that water had entered the system through worn seals. After replacing the seals and performing a thorough system flush, the issue was resolved.
Another example comes from a mining operation in Australia, where operators faced frequent water contamination due to constant exposure to moisture in the air and water from mining activities. The company implemented a regular maintenance schedule, including frequent fluid checks and the use of water-absorbing filters, which significantly reduced the risk of water contamination and improved the efficiency of the machines.
Conclusion: Keep Your Hydraulic System Clean and Dry
Water contamination in hydraulic systems can lead to serious issues, including equipment downtime and costly repairs. By recognizing the signs of water contamination early and following the proper methods for removal, you can prevent long-term damage and ensure that your equipment remains in optimal condition. Regular fluid checks, system maintenance, and preventive measures such as the use of water-absorbing filters are key to keeping your hydraulic system running smoothly.
By taking proactive steps to address water contamination and maintaining the integrity of your hydraulic fluid, you can extend the lifespan of your machinery and avoid costly repairs in the future.