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Hydraulic Fluid Leaks

Hydraulic systems are a huge part of construction. They allow a lot of difficult movement through their unique fluid pressurisation, ensuring that various types of work on the field get done efficiently. This work is anything from construction tasks to even piloting aeroplanes. That’s why your efficiency and safety are compromised when that key fluid leaks from the system. 

The Importance of Hydraulic Fluid

Hydraulic fluid fulfils the specific requirements of the engines they run. The unique advantages of Hydraulic Fluid allow it to serve quite a few different functions that the machines they service require, making them an efficient and cost-effective choice in comparison to alternatives.  


Those requirements are as follows: 


  • Power Transmission – Hydraulic Fluid’s primary function. Essentially, the fluid is pressurised and pushed to one end of the system from another. The force of the fluid being pushed, in turn, causes pressure on other parts of the system – like pistons, cylinders and motors. This allows them to operate. 
  • Lubrication – A lot of components in the machine are close together, which creates friction when they are in operation. That being said, hydraulic fluid acts as a lubricant, allowing components to come into contact and slide past each other without any real damage. 
  • Heat Dissipation – Whilst hydraulic systems are lubricated by the fluid and damage is minimised through it, It still causes a lot of heat. The fluid helps dissipate the heat through its material makeup, ensuring that systems do not get too hot. 
  • Sealing – Hydraulic fluid has a sealing effect that ensures that the hydraulic system keeps air out, ensuring that the system is fully closed off from the outside. This is important, as air getting into the system means that vital components can become contaminated.
  • Contamination Removal – Over time, debris, either from the outside or from wear inside the system, will get stuck within. However, hydraulic fluid has the capability to collect and transport these contaminants to areas like the filters, or the reservoirs, removing them from the system. 
  • Protection Against Rust and Corrosion – Similarly to contamination, fluid helps against rust and corrosion. However, this is more due to the additives in the system preventing any buildup of either element. 
  • Chemical Stability – Hydraulic fluids are formulated so that they don’t break down over time, meaning that the fluid will operate at maximum efficiency. 


The list above should illustrate why a hydraulic fluid leak is a disaster. 

Causes of Hydraulic Fluid Leaks 

Hydraulic fluid leaks can be caused in a variety of ways. Ensure you bear the following in mind: 


  • Component Wear and Tear – Over time, the components of your hydraulic system will wear down. This is due to the components facing repeated friction and pressure. This is never good, as eventually, the components will break or become ineffective. For example, seals. Due to constant pressure, a seal might wear away, which results in water and other such outside elements getting into the system and compromising it. 
  • Improper Maintenance Routines – In order to catch problems and provide solutions in trying to keep hydraulic systems in tip top shape, regular maintenance routines must be put in place. Neglecting proper maintenance routines, such as identifying and replacing degrading parts in the machine will inevitably lead to damage spreading throughout the whole system. 
  • Faulty Installation or Manufacturing Defects – This is, of course, one of the more unfortunate causes – the fact that a brand new component could lead to a hydraulic fluid leak if installed incorrectly. The only way to catch this is to ensure you only work with people that have a high standard of care. 
  • Temperature Fluctuations – Systems that operate within environments that have a wide temperature range can face challenges due to the effects heat and cold has on the material. Temperature changes cause a lot of expansion and contraction within components. This can weaken components over time, making them less efficient, which could in turn cause a leak. 

How to Mitigate the Chances of a Hydraulic Fluid Leak.

To minimise the chances of a hydraulic leak, it’s a good idea to do the following: 


  • Check Regularly – Inspecting the hydraulic system periodically is a good way to ensure that your components are undamaged and running efficiently. Ensure you check the hoses, seals, valves and connectors – going through a list of vital components until you’re satisfied each is in good condition. 
  • Quality Components – Good machines are a combination of good, well-installed components. Ensure that your machine reflects this, as it will go a long way in avoiding damage. Their expense will pay for itself in the long run when you find you have to replace components much less frequently than you would otherwise. 
  • Temperature Management – It is best to buy machines or use materials with good thermal stability. Implementing insulation and cooling mechanisms ensures steady temperature. This will, of course, reduce the contraction and expansion of materials. 
  • Training – Ensure that your operators and the personnel responsible for maintenance are properly trained up to date to modern standards. They must understand the working of the system, have the ability to identify leak points, and have the means to address any issues and ensure they are dealt with in a timely fashion.
  • Regular Fluid Checks – The level of your hydraulic fluid should be measured regularly. By doing this, you can look out for sudden, unexplainable drops outside the margin of error. Whilst the fluid levels are being checked, they should also check that it’s free from contaminants. 
  • Environmental Controls – Ensuring you can control the environment is a good idea in areas prone to dust, moisture etc. By adding preventative measures to ensure these contaminants don’t get into the machine. If the hydraulic fluid is ever contaminated, damage and leaks is more likely. 
  • Leak Detection Tools – Utilising tools like the ultrasonic leak detector, or fluorescent dyes, can help you detect leaks when you suspect them. This is particularly useful in larger machines, as it’s easier to miss more subtle leaks. 

How to Fix Hydraulic Fluid Leaks?

The following are ways you can fix a hydraulic leak when they occur, sorted in the areas they are most likely to occur for your convenience: 

Hose Connections


  • Tighten Loose Fittings – Over time, hose connections can come loose, requiring tightening. You can tighten these loose connections using a wrench. You should do so slowly, stopping when the fixture is snug. Do not force it further, however, as this can result in damage. 
  • Replacing Damaged or Old Hoses –  Hoses are constantly facilitating the fast movement of pressurised water. As such, they are constantly being worn down bit by bit. Over time, you will have to replace some of these hoses. 

 For Seals and O-Rings


  • Disassemble Component – Using a container, ensure that you fully drain all of the fluid that is in the system. It’s important that you ensure none of it spills. After that, take apart the component whilst keeping the pieces organised.  
  • Replacing Faulty Seal or O-Ring – These components are responsible for keeping the fluid inside the machine and preventing it leaking at certain areas. When damaged, it’s imperative to replace them. 
  • Reassembling and Refilling – With the seals replaced, it’s time to do the same with the hydraulic fluid. Once you’re certain everything is sealed, simply refill the system with Hydraulic Oil. 

Hydraulic Cylinders


  • Draining the Cylinder – Before fixing the leak with the hydraulic cylinder, we must first get rid of the hydraulic fluid. Ensure you have a container to dispose of the hydraulic oil. 
  • Disassembling and Inspecting – This is much like checking the inside of a clock. Simply open up the cylinder and inspect the insides for any ruptures or fissures.
  • Replace worn components – So the cylinder may have a rupture inside, or perhaps its damaged at the seals. Either way, highlight the area damaged and replace it with new, strong components.
  • Reassembling – Once all is done, put the machine back together. Then, fill the system with new hydraulic oil. 


Hydraulic Fluid Leaks Conclusion

We hope this article has met its intention in helping people understand what a hydraulic leak involves, and what to do if one should arise. 

Hydraulic Fluid Leaks – FAQs

Can Hydraulic Fluid be harmful? 

Yes. Hydraulic fluid is about as dangerous to inhale and consume as heavy household cleaning products. It also cannot be allowed to come in contact with human skin for a prolonged period of time, as this can result in heavy irritation. Always use gloves, and work in a well-ventilated area to ensure that minimal fumes are breathed in. 

How to Dispose of Hydraulic Fluid? 

Disposing of Hydraulic Fluid relies on specific measures. This is because simply tossing out hydraulic fluid is illegal, due to the risk of damage to the environment. As a result, you must contact a special facility or a recycling centre that handles getting rid of these things. 

What’s the difference between Hydraulic Oil and Hydraulic Fluids? 

The best way to explain this is thus: not all hydraulic fluids are oils, but all oils are fluids. Hydraulic Oil is simply a subcategory of hydraulic fluids. This means that the hydraulic fluids you’ll be filling your hydraulic machine with may or may not be an oil – it all depends on what your machine needs. 

Can Hydraulic Fluid go bad?

Yes. Hydraulic fluid, over time, degrades to the point that it cannot be used to anywhere near the same level of efficacy. This is why it’s important to do regular maintenance, as this is one of the things you’ll be looking for. 


Aside from that, temperature changes for long periods of time can result in massive changes to its very nature. 

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