303 oil

Gene Davis (Ga.) · Jun 3, 2021

I have an almost full 5 gallon bucket of Tractor Supply Co. 303 oil. Will it be alright to use it in a hydraulic system that calls for 15 W-40 motor oil. There are no transmission or final drive parts touched by this oil, just the pump and the cylinders along with the control valves. Gene Davis Tennille, Ga.

Steve@Advance · Jun 3, 2021

If it were mine, I would probably use it.

Since it calls for motor oil, it must not need AW protection.

Here is some information on it.
Tractor Fluid vs Hydraulic Oil

SVcummins · Jun 3, 2021

I do all the time . Just make sure it isnt half water like the tsc oil usually is . I bought 6 pails 4 had water in it tsc is the place Ive had trouble with water

SVcummins · Jun 3, 2021

That page has some misinformation 303 is tractor hydraulic fluid

Check Break · Jun 3, 2021

(quoted from post at 10:30:18 06/03/21) I have an almost full 5 gallon bucket of Tractor Supply Co. 303 oil. Will it be alright to use it in a hydraulic system that calls for 15 W-40 motor oil. There are no transmission or final drive parts touched by this oil, just the pump and the cylinders along with the control valves. Gene Davis Tennille, Ga.

I wouldn't. 303 is a 20wt oil. If your system needs a 40wt oil at higher temperatures, 303 isn't going to do the job. There's plenty of cheap 15-40s out there so why not stay with the spec.

kencombs · Jun 3, 2021

I don't know your application, but I own and have worked on a lot of the little Case/Ingersoll garden tractors. they are a hydraulic drive, not hydrostat, with a fixed displacement pump and motor and a metering valve to control speed. They spec a 20w40 motor oil. That is hard to find and expensive, so most use 20w50 or 15w40 depending on the climate and the level of wear in the system.

I've encountered a lot with 303 or other hydraulic oils. I encountered them because they would not develop the correct power or ground speed with those light weight oils. Your decision.

Gene Davis (Ga.) · Jun 3, 2021

Thanks for the info and advice folks. I will meditate on it a little longer. The machine is my Dig-It brand TLB unit. It is powered by an 18 hp air cooled Kohler flat twin and is a hydrostatic drive unit. That uses A T Fluid in a separate reservoir This would be in the hydraulic system only. I just hated to do away with a bunch of oil if it would work OK. Thanks again for your time to answer the question for me.

Later, Gene Davis

showcrop · Jun 3, 2021

303 is just fine for machines without cutch packs or wet brakes. UTF can absorb only 1% water and still work properly. Many old tractors will get way more than that, and then the owner is asking about his coffee milk shake oil.

Bud Sather in MT · Jun 4, 2021

I did not waste the oil in my bucket 0f 303, I burned it in my wood stove that is in the garage. Bud

sotxbill · Jun 4, 2021

maybe....,,,

303 oils were superseded when higher pressures and flow rates required in neweer model tractors... generated more heat. SO in most tractor hydraulics after 1976-80, they no longer were suitable AND>>>> the key viscosity additive was whale oil which became banned by an international treaty... so overnite these fluids fell out of favor and newer mineral oils with modern viscosity improvers... had to be specified. 303 fluids could be run in applications where there were wet brakes and wet clutches and were very close to "type F" auto transmission fluids.

so yes as a basic hydraulic only fluid, it would probably work fine.

There are a lot of pre 80s backhoes/tractors out there still using it.

303 oil

Gene Davis (Ga.)

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Steve@Advance

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SVcummins

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SVcummins

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Check Break

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kencombs

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Gene Davis (Ga.)

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showcrop

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Bud Sather in MT

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sotxbill

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