Although most people are under the impression that new hydraulic system lubricants are clean – this is far from the truth. Unfortunately it’s not every manufacturing process that ensures that no particles are let loose into hydraulic fluids. At the beginning of every lubricant making process, is the base oil. Then additives are blended in to complete the finished product. It’s then tested to ensure that it works as it should do with the right characteristics. If for some reason, this is not the case then an adjustment is made to bring it in line. Manufacturers use different ways to blend their hydraulic system lubricant components. Some use a type of blender and others use air to mix it up. However, it’s important to consider what these additives are and how they are added. For example, are they filtering the additives before adding them? Is the air filtered before being used to agitate the blend? If not, it’s highly likely that they’ll contain particles and / or contaminants. Once the lubricants are blended, any contaminants should be removed by filtering the liquid. It’s also important that breathers are provided for the lubricant storage tanks. A j-tube vent is not enough. You should also know whether the blender of the hydraulic system lubricant uses new drums or reconditioned drums and whether there are any self-determined specific cleanliness measurements for them to adhere to. New drums can bring contamination due to their manufacturing process, and reconditioned drums can also bring particles from previous fluids. If the lubricant is going to be added to a tank, then it should be filtered beforehand. The tank should be of a particular cleanliness. How was it cleaned? With diesel fuel or was it steam cleaned? As you can see there are many ways that lubricants can be contaminated – by doing your research you can find out a lot and avoid dirty lubricants from entering your hydraulic system.