power steering oil on cat 12 grader?

Hello,

I need to find out what kind of oil to put in the power steering on my 1955 cat 12 grader?

The manual says to use the same oil as the crankcase, but I plan on using 15w-40 in the crankcase and I would think the detergents in 15w-40 would foam up in the power steering. Can I just use power steering or hydraulic fluid? Or should I try and find some 30 weight oil?

Thanks

It's not real critical. I don't think the 15W40 will foam, or you can use something else. I don't think 30 wt will be required and might be sort of sluggish in cold weather. Hydraulic oil will work fine if you want to use it.

Thanks ccjersey, thats what I needed to know!