With so many options available, choosing the right hydraulic oil for your machinery is difficult. Most hydraulic systems may use a variety of oils, so it’s a matter of figuring out which one is best for you.

If you use the wrong type of hydraulic oil, your machinery’s parts will have a shorter lifespan and perform less efficiently.

To avoid this problem, you’ll need to use the best hydraulic oil to ensure that your components last as long as possible.

What You Need To Know About Hydraulic Oil


The viscosity of hydraulic fluid is the most important factor to consider when selecting the right hydraulic oil. If you choose the wrong viscosity grade for your machine, you will notice the poor performance of the hydraulic system.

Ideally, you should match the viscosity grade to your system’s operating temperature. The proper hydraulic oil viscosity will aid in heat dissipation, air release, and mechanical and volumetric efficiency.

In general, as hydraulic lubricant heats up and thins, its viscosity decreases. This is why it’s critical to choose an oil suited to the operating temperature, as it will provide the optimal level of lubrication.


You should also consider the hydraulic oil additives. A variety of additives can be added to make it more or less efficient depending on the hydraulic equipment.

There are two types of additives used to give the oil anti-wear properties that form a very thin layer on the metal surfaces to keep them from touching.

You can also use a rust inhibitor to coat the metal and keep it from corroding from water.

Thermal/Oxidation Stability

When hydraulic fluid reacts with oxygen, it can produce acidic byproducts which will cause oxidation.

So, look for the type of hydraulic oil that will remain relatively stable even at high temperatures.

Water and metals, as well as temperature, will influence the oxidation of hydraulic fluids.

Air Release

Any trapped air must be able to escape. Air bubbles are likely to form since it is being squeezed into a limited space.

Therefore, air should be discharged while the hydraulic system functions. Cavitation and poor efficiency will occur if there is any air in the system.

Water Release

The hydraulic oil will also need to release water, which is introduced to the fluid via air humidity.

You should be aware of this potential problem because it can impact the entire machinery system and create rust and corrosion.

Hence, choose a water-releasing oil. If water is an issue, use a rust inhibitor for your hydraulic system.


Is it possible to filter the hydraulic oil to remove particles and contaminants?

Some contaminants will almost certainly get in, but if you’re operating in the field with a garbage truck or an excavator, it’s even more likely.

The right hydraulic oil with good filterability will keep your machinery useful for longer.

Next read: List of Heavy Machinery that Use Hydraulic Oil

Choose the Right Hydraulic Oil for your Machinery

It may be difficult to pick the right hydraulic oil, but it’s usually a matter of common sense.

Your machinery should come with lubrication recommendations to help you decide. But you can also speak with a certified hydraulic oil supplier to learn more about the ideal options for your machinery.

We can offer advice based on our significant experience to keep your machinery functioning smoothly.

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