Hydrualic Oil versus Motor Oil

[cre10]

Most of the cheap Orschelins and TSC hydraulic fluids are 20 weight. The Rotella is 30 weight.

I have some older tractors where I don't mind the 303 fluid, 20 weight.

On some of the newer stuff it calls for 10w-30 or 15w-40. The 15w-40 is always hard to find and more expensive. Anyone use regular motor oil for hydraulic fluid? I've read online where some say it's totally fine and to go for it and some say heck no don't use it, but don't have any reasons why not. The guys on the heavy equipment forums fight back and forth saying it's fine to use.

Thinking it would be super easy to have a 55 gallon drum of 15w-40 oil for all the trucks and tractors.

 

[the old grind]

Some makers specify 'motor oil' (Terramite says 15w-40) vs hydro, presumably for the additive package if nothing else. If so, shouldn't the 'weight' be as much a matter of seasonal adaption (temp) or to address (YMMV) leaks/weeps?

btw: Hesitate to answer a question with a question, or use the word 'if' lately, but sometimes you have to participate (subscribe) to learn something ... er' if not just to raise your post count.

 

[Bigfoot62]

I do keep a drum of 15w-40 motor oil for all of my engines, but I don't use in the transmissions or hydraulic units. I use MobilFluid 424 for that. I get it in 5 gallon buckets from my fuel supplier.

 

[J_J]

There are a lot of people that just don't know about the fluids. When the manufacturer suggest using motor oil , what are you going to do

A lot of manufacturers do specify motor oil in their machines.

Hyd fluid have special properties, and motor oils have special properties in it.

My Power-Trac and all Power-Tracs use multi grade motor as the hyd fluid, and have been dong it for over 20 years.

A lot of machines use ATF for the hyd fluid.

So use what the manufacturer suggest of make your own decision.

Some hyd fluids don't works with some brake systems.

Find the weight class of fluid that is good for your climate.

If you rent attachments, you are going to mix fluids unless you do a good flush.

 

[cre10]

I do keep a drum of 15w-40 motor oil for all of my engines, but I don't use in the transmissions or hydraulic units. I use MobilFluid 424 for that. I get it in 5 gallon buckets from my fuel supplier.

What viscosity is that?

 

[cre10]

I guess for me I'm just lazy and would like all my machines to run the same :laughing:

Here's a pic of what one of my Case tractors calls for.

 

[Bigfoot62]

What viscosity is that?

I guess for me I'm just lazy and would like all my machines to run the same

I do run the 424 in all my machines. It meets all the specs for tractor/hydraulic fluid. (Ford, JD, NH)
MobilFluid 424

 

[MHarryE]

At Caterpillar we recommend DEO (Diesel Engine Oil) as a hydraulic fluid in almost all machines although it is not first choice for one reason - it costs a lot more than hydraulic oil. Many of our machines, however, have 15W-40 as the only lube for use when ambients are over 40 (104 degrees F). Mobilfluid 424 is a good multi-vis hydraulic oil, roughly equivalent to 10W-30. That same fluid is available at a Cat dealer as MTO (multi-purpose tractor oil).

 

[Diamondpilot]

I have a unit that calls for Castrol 20W50 synthetic Motor Oil only for the hydraulic system.

Chris

 

[CJONE]

I have a unit that calls for Castrol 20W50 synthetic Motor Oil only for the hydraulic system.

Chris

Ouch, that could be expensive if it holds a lot. To the OP, Basically like JJ said it all comes down to weight and the additive package. One of the mechanics around here always said any oil is better than no oil!! A lot of truth to that. CJ