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A Clean Hydraulic System

A Clean Hydraulic System

A Clean Hydraulic System – How to Avoid Contamination

All hydraulic systems need protection from contamination. Over time, microbes, abrasive particles, corrosion, dust, dirt, water, chemicals and tiny pieces of metal will get into the hydraulic system, and without the right hydraulic filtration system in place, these will cause serious damage to the sensitive components inside.

In this post, we look at some of the most common causes of contamination, and how you can effectively protect your hydraulic system to extend its life and minimise the risk of costly damage.

Hydraulic fluid

It might look clean and have come straight out of the bottle, but even new hydraulic fluid is contaminated. Oil picks up contaminants whilst in storage tanks, and the level of cleanliness and water content can do damage to hydraulic systems.

The rule of thumb to follow is that oil is never clean until it has been filtered. With new hydraulic fluid, one of the most effective ways of conditioning it is with a dedicated off-line circulation loop (kidney loop filtration).

Hydraulic components

Hydraulic components are intrinsically contaminated! It’s known as built in contamination, and occurs during the manufacture, assembly, installation and testing process. Metal filings and burrs, dirt and sand are just some of the contaminants that are likely to be found during the initial filtration of a new system.

Maintenance, repairs & servicing

Airborne contaminants, dust particles and microbes enter the hydraulic system every time it is opened for maintenance, repairs, replacement parts or servicing – and are often induced by the maintenance process itself.

Leaving a hydraulic system open for any period of time will encourage contamination, which is why it’s so important to keep it closed whenever possible.

Operation & the working environment

Contamination is inevitable during the day to day operation of hydraulic systems. Wear and tear on the pump, actuators, hydraulic cylinder and hydraulic motor causes tiny particles, which will build up over time, and can cause catastrophic damage to the hydraulic system if not filtered out.

At the same time, external particles can enter the system as a result of the working environment, and where the equipment is operated and stored. Leaky or improperly installed seals and caps can allow abrasive dirt and particles in. Water ingress throughout the system will increase the formation of corrosion, oxidisation, acids and rust into the hydraulic fluid, which can all have a serious impact on the performance and lifespan of a hydraulic system.

A properly specified hydraulic filtration system with a clean filter will prevent ingressed contamination from causing damage.

Wearing Rubber & Elastomers

Over time, seals, hoses, bladders and other parts within the hydraulic system will start to degrade, releasing tiny pieces of rubber into the hydraulic fluid. The best way to avoid this is to check the condition of wearing parts regularly as part of the maintenance and service schedule, and to replace parts as soon as they are showing signs of degradation or damage.

How Alexis Filters can help

At Alexis Filters, we specialise in the supply of high quality hydraulic filters and filtration components including assemblies, filter heads, spin-ons, cartridges and accessories for a full range of mobile, industrial and heavy-duty applications.

Providing expert advice on the right filters to match your needs, we offer unbeatable prices and next day, nationwide delivery on a comprehensive range of products from leading brands Donaldson and Hifi.

For additional information or to order hydraulic filters, please visit or call 01482 711259 today.

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