1
Yarbrough Industries | (417) 8695344 | http://www.yarbroughindustries.com Discover more great content here: https://twitter.com/SpfdYarbrough http://www.youtube.com/user/yarbroughindustries http://www.pinterest.com/yarbroughindus https://www.facebook.com/pages/YarbroughIndustries/150369295060368 KNOWING HYDRAULIC OILS Most hydraulic systems will operate satisfactory using a variety of fluids such as multi-grade engine oil and automatic transmission fluid (ATF), but the most common hydraulic oil is an Anti-Wear (AW) fluid, which comes in different viscosity ranges. Viscosity is one of the most important factors when selecting a hydraulic fluid. It will not matter how well the Anti-Wear, Anti-Oxidation or Anti-Corrosion properties work if the viscosity grade is wrong. The Higher the viscosity grade the higher the operating temperature can be. For example AW22 would be for a cold climate and an AW68 would be used in hotter applications. Cold weather will cause the oil to become thick and hot temperatures cause oil to thin. It’s like putting molasses in the fridge or leaving it out in the sun. Different viscosities account for temperature differences. Another application to consider is the tractor hydraulic and transmission fluids. Special additives are put in the fluid to protect the transmission. These additives include Anti-Chatter, Oxidation Resistance, Water Separations and Anti-Foaming. Many people don’t realize that in the mid 1980’s tractor/transmission fluids made a big up grade to the additives that are now required in the newer machines. The old oil commonly known as 303A is not acceptable to use in machines built after 1985, you should use a more modern oil like a J20C. So as you can see that when you are doing hydraulic repairs, hydraulic maintenance or just changing the hydraulic fluid and filters, be sure to use the correct fluid or you could be causing damage to your hydraulic system. The AW (Anti Wear) oils are a good oil for normal hydraulic pumps, motors and hydraulic cylinders. Just make sure to get the right viscosity. But when running a hydraulic hydrostatic transmission pump in a newer unit, be sure to use the proper oils made specifically for hydrostats or transmissions if not, you may be in for a large unnecessary hydraulic repair bill.
