Volume 6, Issue 1 (January 2009)
The Effects of Lubricant Ingredients on New Hydraulic Oil Cleanliness
Although most of the emphasis on hydraulic fluid cleanliness is routinely placed on in-service fluids, more and more attention is being given to new hydraulic oil cleanliness. Nobody would argue that it is important for users to install clean hydraulic fluid in any system, but some have found that some fluids do not seem to clean no matter how much time is spent on preinstallation filtration. Is it possible that certain lubricant ingredients give false positive readings in certain generally accepted particle counting test methods? Some have already proven that the answer is yes. This paper will attempt to evaluate various specific chemical ingredients used to formulate hydraulic fluids, including base stocks and additive components, to determine in further detail which components “trick” particle count tests.