# 303 tractor hydraulic fluid in splitter?



## metalfingers (Dec 22, 2017)

Is this ok to use in a log splitter?  I can't find a definite answer from searching


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## FTG-05 (Dec 22, 2017)

I just got a PM on another site about hydraulic oil as a result of a discussion on tractor hydraulics and someone mentioned 303.

Here's his text, the only thing I changed was one word (bolded and underlined) and separated it into two paragraphs for readability:

"Yeah there is no API standard for a 'premium' Hydraulic oil.   Same as there is no standard for a 'premium' diesel fuel.  A 'premium' hydraulic oil is called... a Turbine grade oil. It has to deal with the oxidation life of the oil.  A regular AW 46, for example, my house brand, has an oxidation life of 5000 hours.  Meaning, the oil will still be good for a minimum of 5000 hours.  A turbine grade hydraulic oil, will have an oxidation life of greater then 10,000 hours.  (A good turbine grade oil should essentially last forever... But minimum, 25,000 hours or so.)

303 Fluid, is mostly made by one company anymore - Smitty's. They're also the #1 buyer of line wash around the United States... So what you're actually getting, when you buy 303 fluid, is a bucket of *bs*.  It's probably not even meeting true 303 spec, if you actually tested it.  Would tractor hydraulic fluid hurt a log splitter?  No.  But the pump is designed for a single viscosity - AW46 typically,  AW68 in extreme hot weather, or maybe an AW32 if you're in the arctic. A tractor hydraulic fluid is closer related to 10w30, it is fairly multi-viscosity.  303 fluid... is not really, it's just junk. A synthetic tractor fluid, such as Kubota UDT2 - is more related to a synthetic 5w30.  The more you know."


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## FTG-05 (Dec 22, 2017)

To more directly answer the question posed by the OP:

I use the 303 when I need a cheap hydraulic oil to flush cycle through a hydraulic system to get rid of water-contaminated oil.  Typically, that requires anywhere from 5-7 drain-refill-run-drain cycles.  In other words, it can get expensive fast.  Once done, I drain and refill with a better hydraulic oil (Kubotas SUDT for example in my RTV). 

In the case of my log splitter, the last item I've had with water contamination, I'll just refill with O'Reilly's Premium Hydraulic oil and call it good.


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