# old motor oil = hydraulic fluid



## rancher1913 (Dec 5, 2008)

my newer john deere skidder uses motor oil for the hydraulic system, came that way from the factory. so if the brains at john deere say it will work what if a person was to filter old motor oil and use it in older loaders that like to use hydraulic fluid. I don't think I'd risk it in a newer machine but I have several old farmhand loaders with a pto pump so the oil would only go to the lift cylinders and not the transmission. anybody ever try this. might have to add some heavy gear oil to the mix to get the right "weight"


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## Old Vet (Oct 15, 2006)

IF the used motor oil is non detergent it will work but not for long. Any detergent in the oil will cause it to foam and when hot will not work the cylinders very well.


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## plowjockey (Aug 18, 2008)

My guess would be, that John Deere, being who they are, _designed_ and _tested_, the skid loader - extensively, to work with motor oil, in the hydraulics.

Other manufactures probably did not - at all.

I'd hate to end up with problems in old hydraulics (like they don't already have some), by putting motor oil in it, especially used motor oil. Who knows what the seals and o-rings will do?

Hydraulic oil is about $35, for 5 gallons, which is not bad, for any kind of oil.


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## farminghandyman (Mar 4, 2005)

unless it is leaking like a sieve, I would not use old motor oil,

(I did have a loader on a old tractor that would lose a quart of oil nearly ever time one used it, out of the cylinders, I did use old motor oil in it, but there a real reason for the use of the old oil, as it would have cost a lot to keep clean oil in it, but if it is not leaking a lot *WHY*,

I know the hydraulic system on the old JD combine says just use there motor oil in it,


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## agmantoo (May 23, 2003)

Caterpillar has used motor oil for many years in certain machines I had a track loader built in the 60's that did this. I would never put burned motor oil in anything hydraulic however.


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## ace admirer (Oct 5, 2005)

first one cannot blend weights and make an average weight,

motor oil does not have the rust and antioxiders (R and O) nor antishear capabilities of most hydraulic formulated oils. but it has been used for decades in some hydraulic applications. but these machine and their maintenance was designed with that use in mind.


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## rancher1913 (Dec 5, 2008)

the detergent would be a problem but I haven't seen detergent oil in years around here. there is no difference in the maintenance on my skidder as opposed to any of my tractors and even talking to the service manager at john deere he said the 10w-40 is almost identical to hydraulic oil. have to disagree on blending oil, you can thin it out and thicken if you have a little knowledge of chemistry, you can't do oil and water but you can change the consistency using similar substances. I would nor risk a transmission on a tractor using it but in a pto pump that is almost worn out and a dedicated system that only uses the oil in the lift cylinders I'm still thinking it would work. figured somebody on here might of tried it as frugal as most of use are.


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## ace admirer (Oct 5, 2005)

hmmmm, i've only had four classes in chemistry (i stayed confused most of the time, although i do remember the red head grad student that taught one of them). the viscosity of petroleum oil is a function of the size of the molecular chain, the viscosity index more closely associated with the shape or bonded shape. you would need a little chemistry and one heck of a chemistry set to do it, a distillation column about 3 stories high(old method, pre 1940) or the chemicals for cracking the bonds and then the chemicals for forming new bonds (new method) either could be done for a couple of dozen million dollars. just adding two oils together is a mixture that is unpredictable in nature or length of duty. perhaps not a problem in low performance old equipment.

motor oil has additives to help combine water (in small amounts) so that it can be evaporated, boiled off as it heats up. hydraulic oil, the opposite, most has r and o inhibitors that do the opposite. new hydraulic systems may have a sealed tank 
(very likely) or a heated section (unlikely) and low shear components, they may deal with motor oil ok,,,,,or perhaps its just a maintenance decision. old systems (mobile, construction) had vented tanks, inhaled humid air everytime an actuator was extended. had high shear valves and mostly high shear pumps. industrial/nonmoble machines usually have low shear valves (all closed/or all open) and are the systems that could sometimes use the easier to obtain motor oil.

even the universal fluid (hydraulic and hp additivies or wear additives) is different that motor oil.

mixing brands of oil in the old days could and would sooner or later spell disaster. with the american MIL and API standardization, somewhat rare today. 

hydraulic fluid and motor oil almost the same,,,,,,, hmmmm. well yeah they both came from dinosaurs.


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## rancher1913 (Dec 5, 2008)

ok i guess ya missed the part about motor oil comes in hydraulic systems from the factory so your spiel about them never being able to work does not hold water. all I was wondering was if anybody had any experiance doing this because I know for a fact it is being done on new machines and as agmantoo said it been done since the 60's.


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## plowjockey (Aug 18, 2008)

rancher1913 said:


> ok i guess ya missed the part about motor oil comes in hydraulic systems from the factory so your spiel about them never being able to work does not hold water. all I was wondering was if anybody had any experiance doing this because I know for a fact it is being done on new machines and as agmantoo said it been done since the 60's.


No one even said it has not been done, or is not possible.

Me, I was just trying to figure out why anyone would even _want_ to pour motor oil, let alone dirty_used_ motor oil, into any hydraulic system, that does not specify using that type of oil. Especially since hydraulic oil is cheaper than motor oil.

My 67 ford backhoe, specifically calls for a grade of hydraulic oil. I go out of my way to match it, when servicing.

I always try to do things right.

You could probably fill the engine crankcase with _olive oil_ and it might run just fine. 

Then again, it might not.


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## farminghandyman (Mar 4, 2005)

rancher1913 said:


> the detergent would be a problem but I haven't seen detergent oil in years around here. .


Unless it is a NON Detergent oil nearly all oil is or equivalent to a detergent oil the additives in the oil that maintain viscosity and the additives that keep the dirt in suspension and neutralize the acids, and keeps it surface tension, there is a lot of additives (which is what was or is called detergent)



> Mobil 1 | Additives
> Answer:
> All modern high quality engine oils are detergent oils. A non-detergent oil basically has little or no additive. This would equate to an API SA or API SB oils which are ancient history. An oil with little or no additive will certainly shorten the life of the engine or most other equipment in which it is used.


many of your Hydraulic oils are actually have more "detergent" or additives in them than motor oils, there diffrnet additives, that is my understanding any way,
good information below,
http://www.greenpartstore.com/assets/images/Oil_Sales_Guide.pdf


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## davel745 (Feb 2, 2009)

ace admirer said:


> first one cannot blend weights and make an average weight,
> 
> motor oil does not have the rust and antioxiders (R and O) nor antishear capabilities of most hydraulic formulated oils. but it has been used for decades in some hydraulic applications. but these machine and their maintenance was designed with that use in mind.


This is the main reason to use recommended oils in your machine. 
Ace got it exactly right. Used motor oil in hydraulics will (even when filtered) damage the seals and pistons almost beyond repair. My suggestion is. If your system leaks fix it.


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## Darren (May 10, 2002)

No one's mentioned the other stuff used motor oil contains. Depending on the engine it came out of, you could have all sorts of nasty stuff. The pH could be wrong, Almost certainly the particles that get through the filter wouldn't help the close tolerances in an hydraulic pump.

As others have mentioned the additive package added to lubricating oils wasn't designed for a hydraulic system. If the hydraulic system was designed for lubricating oil, that's a different story. However, the design team never figured someone would add used oil to the hydraulic reservoir.


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## sammyd (Mar 11, 2007)

why why why?
Good Lord, use the proper oil as recommended by the manufacturer.
Want to use old motor oil for something? Get a waste oil burner for the shop in winter.


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## agmantoo (May 23, 2003)

Not far from me is a man with a sawmill. He has a large forklift for loading logs onto the carriage rack loading equipment. I was at his place and he had a 5 gallon bucket tied under one of the arm cylinders to catch the leaking hydraulic oil. He is catching the oil and filtering it through a rag as he puts that dirty oil back into the reservoir!


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## ace admirer (Oct 5, 2005)

i used to be able to follow a trail my tracked hoe left,,with the price of fluid,,,i replaced the seals....


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## plowjockey (Aug 18, 2008)

agmantoo said:


> Not far from me is a man with a sawmill. He has a large forklift for loading logs onto the carriage rack loading equipment. I was at his place and he had a 5 gallon bucket tied under one of the arm cylinders to catch the leaking hydraulic oil. He is catching the oil and filtering it through a rag as he puts that dirty oil back into the reservoir!


That sound's fine, but it's not the same, with used motor oil, which contains microscopic dirt, carbon, plus sludge or other contaminants, that will not filter out through a rag.

If the hydraulic system is toast and one really does not care about it any more, then about any kind of oil will get the job done.


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## Old Vet (Oct 15, 2006)

rancher1913 said:


> the detergent would be a problem but I haven't seen detergent oil in years around here. there is no difference in the maintenance on my skidder as opposed to any of my tractors and even talking to the service manager at john deere he said the 10w-40 is almost identical to hydraulic oil. have to disagree on blending oil, you can thin it out and thicken if you have a little knowledge of chemistry, you can't do oil and water but you can change the consistency using similar substances. I would nor risk a transmission on a tractor using it but in a pto pump that is almost worn out and a dedicated system that only uses the oil in the lift cylinders I'm still thinking it would work. figured somebody on here might of tried it as frugal as most of use are.


Around here most motor oil will have a detergent in it like Havoline and such. You can buy non detergent oil in most places and it is higher than most any major brands.


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## Evons hubby (Oct 3, 2005)

plowjockey said:


> You could probably fill the engine crankcase with _olive oil_ and it might run just fine.
> 
> Then again, it might not.


I dunno about olive oil... but I used wesson cooking oil once years ago in my vw to get me to town and get some motor oil. It was only a few miles to town and back, and I ran it easy. No real harm done but that durn thing smelled like french fries every time I fired it up after that.


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## poorboy (Apr 15, 2006)

Use to work for a company that had several Cat. loaders, we ran a 10-40 Mobil oil with non foaming properties in them , only used new oil out of the barrels..


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## plowjockey (Aug 18, 2008)

Interesting.

I remember reading a couple of years ago, that someone purchased a cheapie Chinese "crate tractor", (needing final assembly) where the hydraulic system was filled with motor oil.

They thought (so did I at the time), that maybe they incorrectly filled it with the wrong fluid, but did not have a decent service manual, to compare what fluid was required.

Apparently, they use motor oil too.


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## GoldenCityMuse (Apr 15, 2009)

I have NO knowledge of this.

SO, if I had to use something, I would rather use ATF fluid that was used instead of motor oil.

There, worth every nickle.


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## haypoint (Oct 4, 2006)

My Russian tractors use 40W motor oil for the hyd. system. Neighbor has a 70 year old tractor with a loader. Uses used engine oil in the hyd. Has for 40 years at least. Does it because the cylinders leak.


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## haypoint (Oct 4, 2006)

The big oar hauling freighters use a lot of hyd oil. At one time, you could get all the barrels of used hyd you wanted. Looked as clean as when it was new. Not sure where it goes now.


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## jefferson (Nov 11, 2004)

I have a 50+ year Case 420B back hoe. The maintance manual lists different oils by the page. I was going broke getting things right. I talked to a case Mech and he said to use hydrolic in everything but he power steering and I would be fine. Haven't had a prob.....except in the power steering unit.


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