SAE 10W for hydraulic oil ??

Gordon Gould · Jun 7, 2011

I have a new to me Dresser dozer that specifies API CC/CD SAE 10W oil for the hydraulic system. In a footnote it says the hydraulic oil must pass the TO-2 test. Can anyone tell me what the TO-2 test is ? Does this make it special oil or can I use any good quality API CC/CD SAE 10W oil ??
Thanks

MHarryE · Jun 7, 2011

TO-2 is a Caterpillar specification for hydraulic oil. Although it is a rather old Caterpillar spec, it doesn't mean you need to have a Caterpillar oil. Instead it means the oil meets certain hydraulic oil specs. Often you will see on an oil company spec sheet that a certain oil meets Caterpillar TO-2, Allison C3, and other specs I can't think of right now. Basically the spec is for hydraulic oil used in mobile equipment as opposed to industrial hydraulic oils intended for use in stationary equipment like a hydraulic press. As an example you can go to this site and find the spec sheet for an oil that meets Cat TO-2, and you will find it meets a whole host of other company oil specs.

Mobilfluid 424

Gordon Gould · Jun 8, 2011

Thank you. So looking at the Mobilfluid sheet I would guess that when it says to use 10W Motor Oil that meets TO-2 they don't mean a motor oil designed for internal combustion engine use ?
Knowing that is a Cat spec is a big help - now I should be able to find out.
Thanks again.

MHarryE · Jun 8, 2011

I was tired last night when I responded. TO-2 is a transmission oil spec - the TO stands for transmission oil. That doesn't mean not for use in hydraulic systems, but it has properties that make it suitable for use in power shift transmissions and final drives where clutch and brake discs can be damaged. I picked Mobilfluid 424 as an example because if you go down the list, you will see it is their recommended oil for meeting John Deere, Kubota, Case New Holland, and many other tractor company's combination hydraulic/transmission oil.

I am not sure what your Dresser dozer uses the hydraulic oil for other than for the hydraulic system. I do know that Cat specifies their diesel engine oil for use in hydraulic systems in high temperatures - temps consistently over 104ｰF. The problem with diesel engine oil is it is very expensive compared to hydraulic oil. I think you would do well with engine oil if it is used only for hydraulics, but if it goes into a power shift transmission or something with wet disc brakes, I would look for something else. Mobilfluid 424 or any of the similar oils. If you look at the numbers for viscosity at 40ｰC and 100ｰC, you will see it is just a little heavier than 10W but much lighter than 30.

I have a Cat mini-excavator and I use Cat Hydo Advanced 10 hydraulic oil in it. I've attached a link that if it works for you, shows a comparison between this oil and regular 10W engine oil. Note that it doesn't say anything about being able to meet Cat's TO-2 spec.

http://www.cat.com/cda/files/1386267/7/PEHJ0182-02.pdf

fieldserviceengineer · Jun 23, 2011

Gordon Gould said:
I have a new to me Dresser dozer that specifies API CC/CD SAE 10W oil for the hydraulic system. In a footnote it says the hydraulic oil must pass the TO-2 test. Can anyone tell me what the TO-2 test is ? Does this make it special oil or can I use any good quality API CC/CD SAE 10W oil ??
Thanks

In another life, I worked for a Caterpillar dealer as a mechanic, trainer, and technical contact guy. Caterpillar specified 10w engine oil as hydraulic fluid. They also used 50w engine oil as gear lubricant in stead of 90w. The engine oil and the gear lubricant had the same viscosity just different way of measuring viscosity. Cat philosophy was having all engine-type lubricants made maintenance easier for the customer.

Diamondpilot · Jun 23, 2011

I have a Chinese Tractor, a Jinma 284, and it calls for 10W 20W or 30W motor oil in the hydraulics depending on location. I run AW32 hydraulic oil as most Chinese tractor owners do.

What I have been told, may or may not be true, is that some of these machines have these specs because of the parts of the worlds they come from. Its not as easy to get your hands on specific oils as it is here. They did this to simplify things.

Chris

MHarryE · Jun 25, 2011

Diamondpilot said:
I have a Chinese Tractor, a Jinma 284, and it calls for 10W 20W or 30W motor oil in the hydraulics depending on location. I run AW32 hydraulic oil as most Chinese tractor owners do.

What I have been told, may or may not be true, is that some of these machines have these specs because of the parts of the worlds they come from. Its not as easy to get your hands on specific oils as it is here. They did this to simplify things.

Chris

As a person who specified the oils for a manufacturer, there was a reason, at least in our experience, for using engine oil or oil specialized for mobil hydraulics. Industrial oils (AW grades) are formulated so water will settle out and can be drained before a stationary machine starts for the day. On our mobil equipment this water (from condensation) settling to the bottom of the reservoir can be sucked into the hydraulic intake as a nearly 100% water slug. This shot of water will damage hydraulics, especially piston pumps and motors. Engine oils and mobil hydraulic oils emulsify the water, at least the small amounts that come through normal condensation, and it won't hurt the components. Earlier in my career I worked for a combine manufacturer. We shipped our combines with industrial hydraulic oil in the system and every year had to replace a significant percentage of hydros under warranty where the failure mode was identified as water damage.

ModMech · Jun 25, 2011

If the "oil" you propose to use meets the specification, or betters it, you can use it without much concern. I say much because there is a chance that a new oil formulation will be incompatable with a VERY OLD system, it is unlikely but very possible.

I used 15W-40 engine oil, that met both TO-2 and C3 specs in Allison transmissions for years, as well as in the diesels in front of them.

Gordon Gould · Jun 29, 2011

Thanks for all the responses. I have been away from my computer for while and I'm sorry that I am slow getting back. I am trying to learn about hydraulic oils.
My new to me dozer has an independent hydraulic system consisting of tank, pump, valve, and 6-way blade. Nothing else. The manual says use 10W motor oil or Dresser Hydraulic Transmission fluid. On the motor oil it doesn't say anything about detergent or non-detergent. Anyway, I can get a 5 gal pail of 10w for about $80, 5 gal of permatram III for $115. Then the guy at TSC and the guy at Bond Auto say use AW-32 for $39 or no-name Hy-Trans oil for $59. I need 15 gal for the hydraulic system.
Then I also have a 20 gal transmission system ( torque converter and transmission with wet clutches and brakes ) It also calls for either 10W motor oil or Dresser Hydraulic Transmission fluid also. I would like to use the hydraulic trans fluid for every thing but don't understand the difference between Permartran III at $115/5 gal and Bond Auto Hy-Tran Oil at $59/5 gal. I need a total of 35 gal so there is some money involved.
Sounds like I should not consider AW-32 in the hydraulics.
Thanks for your comments in advance.