Low visosity hydrolic fluid

[J_J]

Thanks Glastron23. I just took a look at the spec sheet for the J13 oil and ours performs a bit better. The J13 has a VI of 300 (resistance to viscosity change with temperature) while our MV15 is 356 and the viscosities are very comparable otherwise. Our normal oil MV22 does well with 253 VI for our temperatures, but like I mentioned there are issues with very small lines on some equipment. When the UTEM booms come here from Texas they'll put a 32 oil in them, we make sure to order those empty so we can put our own in, during winter they become unusable.

Engine oil and hydraulic oil serve two different purposes, hydraulic oil is used to transmit power while engine oil is used as a solvent and lubricant which is actually pretty close to water (without the rust.)

I have to disagree with you on your assumption about motor oil. Our Power-Tracs, Case equipment, and other large machines use motor oil as hydraulic fluid , and some have been using it as hydraulic oil for 30 year. You want something that is thin enough to flow well in cold climates, and not be to thin for high temp areas. 10W-40 motor oil is what we use. It works quite well. Some of us are using synthetic motor oil as the hydraulic fluid.

 

[wdchyd]

Meyers snow plows are a problem in cold weather.
Most users I know use automatic transmission fluid (ATF).*
Works great!

*ATF is hydraulic flud, just thinner than our tractor 'universal' type.

And low-temp aircraft oil is even better..!!

 

[Rocwin]

J.J., I didn't mean to say that it couldn't be used as a hydraulic fluid but when a motor oil is used in a motor it's purpose is not to transmit power, but to lubricate and be a solvent. However because of the detergents and some additives it might be best to stay away from using motor oil in some hydraulic power applications.

 

[JCByrd24]

Snow plow oil is usually the same spec as aircraft hydraulic oil, design for low temp ops ,and might be more available to you and less expensive that aircraft hyd oil. Usually branded by a plow company, but some generics out there too. By the way, plow oil works way better in meyer plow units than ATF, it has something like 13x less (or more, whichever is thinner) the viscosity rating of common ATFs a 0 degrees.

 

[kjung17]

I think he's looking for fluid power transfer, not lubricity. Why not brake fluid? Why the pulsitile flow? What sort of frequency? Hmmm...are you using a paristaltic pump? God, I'm such a nerd.

 

[SPYDERLK]

FYI, the viscosity of engine oil when it reaches operating temperatures is very close to the viscosity of water.

Mace, do you have figures on this? Im curious.
larry

 

[J_J]

Have you guys noticed that netmo, the original poster has not posted since his first and only post. I think he is throwing out nibbles and see who bites.

His questions doesn't seem valid.

 

[SPYDERLK]

Yeah. Im not sure why he doesnt add some clarification. His last activity is 12/8.
larry

 

[mmurphy]

Probably a teen ager snickering at us, or a mad scientist!!!!

 

[Mace Canute]

Sorry Larry, just something I read many years ago in a magazine. I don't recall them citing any references.

Water at 20C has a kinematic viscosity of about 1 cSt.

30 weight engine oil should be between 9.3 and 12.5 cSt at 100C and between 420-650 cSt at 20C.

A 10W/30 oil might be 12.4cSt at 100 C while that same manufactures 15W/40 might be 15.5 cSt at 100 C.

As a comparison, milk at 20C is about 3 cSt.

Comparing relative viscosity is a difficult thing to do!

If you go to the bottom of this chart you will see how the viscosity of water changes with temperature...all the way from 1.788 centistokes at 0 C to 0.295 centistokes at 100 C. That's a ratio of 6 to 1. If you take two cups of water, one just at the freezing point and one just at the boiling point, there isn't much difference to the eyeball...if you were to stick a spoon in them and stir them around...but by scientific measurement it seems like a lot. Extrapolating from this, you can see that the difference between water at 20 C and oil at 100 C isn't as great as a person might guess from the numbers. That isn't to say that an engine won't see the difference in oil with such different viscosity, it definitely will, but a person with a spoon? Not so much. I hope you can see what I mean in all of this.