Causes of Hydraulic Fluid Contamination

Fluid contamination is one of the leading causes of hydraulic system failure in most applications. It is important to recognize the potential sources causing contamination to effectively handle the issue at hand. We’ve put together the most common possibilities of how fluid contamination may occur.

  1. Contamination during production

The first question you need to consider is, “how clean is the oil from my supplier?” Hydraulic fluid contamination may unintentionally occur during processing or mixing in the production phase. Suppliers may have little control over how the fluid is stored. This is why filtering all fluids that go into hydraulic systems prior to use is so important.

  1. Contamination during storage and/or transfer

Storage of hydraulic fluids can easily cause contamination as well. Dust, dirt, debris or moisture can enter the container if it is not sealed properly or during fluid transfer. Although moisture contamination isn’t visible, it can cause a major issue known as “breathing.” Breathing becomes a problem when the hydraulic fluid container is exposed to varying temperatures. To prevent contamination during the storage phase, make sure the container is well sealed and kept in a controlled environment. If the container is kept outdoors, it is recommended to lay it on its side to avoid collecting water on top of the container.

  1. Contamination during service and/or maintenance

When fluid is exposed to higher than usual temperatures during service, this can cause contamination. So, it is recommended to change fluids on a regular basis as hydraulic fluid naturally degrades over time. If you believe your fluid has been exposed to higher than normal temperatures or ingested some sort of contaminant, you should flush your system and add new, filtered hydraulic fluid.

It should come as no surprise that fluid contamination can occur during maintenance as well. With all the possible ways contamination can be introduced during maintenance, it is important to make sure you:

  • Clean exterior components using lint-free cloths
  • Cap hoses and plug ports
  • If you are installing a new filter or seal, make sure to leave it in its original packaging until right before installation

There are plenty of other ways fluid contamination may occur, but these are by far the most common. By taking proactive measures to maintain your hydraulic fluid, you can prevent contamination and system failure.