Fluid to use in power steering system

[Geom]

The next question is what fluid to use in the power steering system.

We replaced the power steering pump and hydraulic cylinder, during the rebuild.
When we got the bus there was some confusion as to what fluid to use.
As we refilled it, we had started using hydraulic fluid.
That was a bad idea as as soon after, the system started squealing, leaking, and behaving erratically, leading to more leaks and its eventual demise.
In talking with the folks at Choo Choo, they strongly recommended using 30 weight oil.
We started to use that (mixing in), and things improved marginally, but I think by that time all was done.

I want to make sure that we start off right.
The shop here is recommending dexron 3 ATF in there.

Thoughts?
This is the "original" type of power steering in these coaches.

Thanks again,
George

[Dave5Cs]

Power steering fluid = Wix filters SL 10012, ATF, Any of these are fine Clifford says the Ross book says. About 5 QTS.
Dexron ll
ATF type E or F        or              
Chevron 10/40
Chevron Torque 5 Fluid
Exxon H 32 Hydraulic
Fleet Line PSF
Ford spec M2
Mack EO-K2 engine oil
Mobil ATF 210
Mobil Super 10/40
Shell Rotella T 30w
Shell Rotella 15/40
Texaco 10/40
Texaco TL1833 power steering fluid
Union 10/40
Union 15/40
Unocal Guardol 15/40 there you go. that is the approved oils for your steering box from the TRW book

Thats just what he told me for mine. I use ATF Dexron
Dave5Cs

[Geom]

Thanks Dave!

I'd been doing some research and was concerned that (some have stated) ATF has "seal additives" that might eat away at the seals and cause leaks over time.

But so far, all of the other reputable sources say Dexron 3 is fine to use in there.

I just don't want to end up with the same problem as before.

[bevans6]

I used 10W-30 engine oil in mine.  That's what the manual called for - 10W engine oil.

Brian

[uncle ned]

                          10w 30 weight oil
Alison v730 and power steering oil.  down to just 2 oils to remember to carry.

uncle ned

in a major emergency would put it in the drippy troit.

uncle ned

[Lin]

Ours is just power assist and Dextron work fine.  I have seen it recommended to use the motor oil, but I like my leaks having different colors.

[TomC]

15W-40 for Sheppard power steering along with the Kubota engine for the generator. Straight 40 weight for the 8V-71. Dexron for the V730. Good Luck, TomC

[dtcerrato]

Were running the original Vickers Power assist in our 1953 - 4104. The lubrication charts calls for S19 fluid which is automatic transmission fluid type A or presently known as dextron/mercon III. When we first purchased the bus in 1979 the system was leaking pretty badly. There was no filter on the system so we added a return filter just before the pump. Afterwards we put a tiny amount (at a time over 1 month intervals) of power steering stop leak in until the leak stopped - & now the system runs almost completely leak free for many years.

[Geom]

Thanks a lot for the help! That really helped make the decision.

Based on the general consensus here and from the experience we had using 30w oil (after the hydraulic fluid debacle) I went ahead and told them to use 15w40 oil in there.
The oil they use is Mobil Delvac (1300 I believe).

I like the idea of using/carrying just two oils.
Plus I was concerned that over time ATF might put us back to leaking around the assist cylinder and seals.
And (from what I'm reading) it seems dexron 3 is no longer a "real" thing, as GM withdrew their license for it some number of years ago. So those making it now are kind of going off the board for a 1000. And I'm not sure if the later revisions are truly as backwards compatible with such an old system (original power assist cylinder).

Thanks again!