D6C Hydraulic Oil

I was using Cat 10W hydraulic oil for some years when they came out with it, before that my dad would use Shell 10W engine oil for the hyd. My oil distributor told me the older 10W is what you should use in the old vane type pumps, he recommended Phillips Power Drive 10W hydraulic oil, I asked about AW46, he said no, Cat oil is thin like AW oil also. But everyone you talk to has there own opinion what to use.
https://shop.sclubricants.com/phillips-66-powerdrive-fluid-10w

Where y0u are at wil help also. Are you in a cold climate or not?

Where y0u are at wil help also. Are you in a cold climate or not?

Im in Texas, temps between freezing and 105. mostly 80s-90s

Hi Dutchboy, I had a 'dozer contracting business in Texas for 23 years. I ran D6Cs, D6Ds and a D6H.  I used Texaco Ursa Series 3 engine oil in the hydraulic systems of them all. 10W in the machines when new and 30W when they were higher hours.
The "Tractor Fluid" oils are cheaper, but you get what you pay for. I have a friend that is still in the business here (D8K & D7G) and he says the cheap oils don't perform well in hydraulic systems in the Texas heat.
I still think the single weight oils are best for this application, You can always mix 10W and 30W of the same brand oil to come up with a in between weight if you want.
Craig
 

Craig, do you generally have to get oils like that from an oil dealer? I don't typically see them in auto stores and such

Hi Neil, These days I use Chevron Delo single weight oil, I find it in gallons at many sources here including O'Reilly's.
Craig

 This is what to look for, it is also available in 30W. I use it in our D7E and D6B. 
 [attachment=66439]20220123_103213.jpg[/attachment]
Craig

Do you actually know whats in that oil? or just assume "its good enough" because its Delo? Most oils today are for the "new" style engines not for the older engines which require different specs.