How often should you change your hydraulic filters? We get asked this question often, as contamination is one of the most common causes of hydraulic system failures. Depending on the machinery you use, you may have several different filters trapping contaminants before they can enter critical systems. However, a neglected filter can become the cause of many problems instead of preventing them by releasing contaminants into the system. A neglected filter is a recipe for downtime and costly repairs. Let’s look closer at filters and when to change them.
Filters can have a significant impact on the flow rate of fluids. When they become clogged, hydraulic fluid cannot pass through the filter at the normal flow rate. This can cause pressure drops, which is bad for machinery that must operate within a specific pressure range and can cause damage. It may also cause extreme pressure increases upstream from the filter, which is also bad and has the potential for damage.
Your machinery may have a bypass valve to prevent pressure drops, and while this prevents pressure loss, it allows unfiltered fluid to enter the system. In either scenario, the repercussions are bad for your machinery.
The cost of getting clogged filters leading to contamination is downtime and repairs. You’ll lose productive time tracking down the damage from the contamination, flushing the system and making repairs. The cost of changing filters is negligible in comparison.
The easiest and most cost-effective way to change filters is with a preventative maintenance schedule instead of waiting for the filter warning to light up. Preventative maintenance minimises downtime, puts you in control of downtime and allows you to run your machinery efficiently.
Changing filters regularly, before problems develop, boosts cleanliness of fluid through the entire system. As hydraulic fluid is the lifeblood of the system, keeping it in an optimal state of cleanliness helps the other components run at peak efficiency. Over the long term, your machinery will hold its value better and have a longer useful lifespan.
You can schedule filter changes in one of two ways. First, you can follow the manufacturer’s guidelines, which typically recommend filter changes based on the number of hours your machinery is in use.
While this approach is a good benchmark, it isn’t always reliable. If the filter needs changing before the recommended change time, you risk getting contaminants into your system. If it doesn’t need changing, you’ve lost some of the useful life of the filter. It pays to use your experience with the machinery to develop a maintenance schedule to optimise the useful life of filters.
The second method is to monitor pressure changes across the filter with an element condition indicator. When the filter is approaching capacity, the indicator alerts you to the need to change it. While this method ensures you are getting the full lifespan out of your filters, you don’t maintain as much control with downtime from maintenance, as it pays to change the filter swiftly.
