How Contaminants Affect the Reliability of Hydraulic Systems

Blog | November 19th, 2019

A hydraulic system is essential to making complex and fast-moving machines  work and function. It works by moving energy from a motor to an actuator through the use of pressurised fluid. This pressurised fluid acts in every part of a vessel and creates force or power. This force, whenever applied, can easily lift heavy loads and perform repetitive tasks.

Numerous machines use a hydraulic system. Some of these are excavators, presses, wind turbines, hatches, and cranes.

Although the liquid in hydraulic systems is kept inside the vessel, there are still some factors that can affect the systems’ operations. Contaminants, which can be in the form of various elements, can affect the reliability of hydraulic systems. The effect of contaminants can be catastrophic since the equipment or machinery can be destroyed in the long run. The following are the examples of contaminants and their corresponding effect on hydraulic systems.

Solid Particles

When a machine is used continuously, there will be a high chance that solid particles from outside can get inside the system. Depending on the usage of the hydraulic system, some of the particles that can affect the system are salt, human hair, milled flour, and bacteria. However, the wear and tear of the hydraulic system can directly affect itself. Particles from metal can get inside the system and affect the operations of the hydraulics over time. Some of these metal particles can get stuck on the system and cause malfunctions and a significant decrease in workload efficiency.


Water is considered to be the most common contaminant in hydraulic systems. Both the physical and chemical properties of the hydraulic oil are affected once the water gets into the hydraulic oil found inside the system. Physically, the water can speed up corrosion in metal surfaces and reduce the lubrication of the system. Moreover, a machine placed in a low-temperature environment can result in the crystallisation of water, jamming the components because of ice crystals. Chemically, water can cause additive depletion or deposition and oxidation on the hydraulic system. The formation of acids, alcohols, or sludge on the hydraulic system is evident with water contaminants.


Despite the closed vessels and parts of the hydraulic system, some air can still get inside the system. Undissolved air inside the system components can change the pressure of the machinery, resulting in the compression of air and production of heat in small air bubbles. The compression of air signifies lost of control to the system, while air bubbles cause major damage to pumps.


All kinds of equipment have their own set of operating limitations. Some equipment can perform for a long time, while others can’t to avoid compromising the components inside. These limitations also prevent any sort of overheating and other temperature-related problem. For hydraulic systems, if the heat is excessive, then it would result in additive depletion or chemical changes to hydraulic oil. Overall, the mentioned contaminants affect the reliability of the hydraulic system since they can possibly damage the whole equipment in the long run. Some functionalities of the equipment with hydraulic system may underperform due to the existence of contaminants on the hydraulic oil. If you want to better protect your hydraulics against contaminants, contact us at Mobile Hydraulic Specialties for more information.

Mobile Hydraulic Specialties Pty Ltd

Factory 89, 38-40 Popes Road
Keysborough, Victoria, 3173

Phone: (03) 9798-6511

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Contact Us

Mobile Hydraulic Specialties Pty Ltd

Phone: (03) 9798-6511
Address: Factory 89, 38-40 Popes Road, Keysborough, Victoria, 3173