1594 power steering oil ???

Hi i think universal will do in these ok .

Martin

If unsure then use a 32 grade hydraulic oil.

Hi Guys:

I basically agree with the above recommendation to use ATF. I did for years in my 1212. Only problem is that my seal is seeping - allowing ATF into the engine oil. Since the ATF has detergents in it - it is more likely to slip past the seal and also more likely to loosen deposits in the old engine.

So I switched to synthetic 5W-30 diesel motor oil.

Hope this helps!
Chris

Yes, back then I thought it was an external leak but after I refilled it - it became obvious that it was leaking internally also. Hence, I switched over to motor oil.........

Hi John:
While I basically agree with you that ATF is the best choice I don't necessarily agree that synthetic 5W-30 diesel oil is any heavier than ATF which is 20W.

I can tell you from experience that my steering feels exactly the same whether I use ATF or 5W-30.

If you don't 'deal with the leak' (which I have not), too much ATF in the engine sump can loosen up old deposits which in fact can be harmful to the engine.

I too was skeptical some months ago when I brought up the original thread. Thinking that light motor oil was not a good idea - but now, after running all this time with it and suffering no ill effects I think that it might be just fine.

Just my .02 - definitely NOT worth arguing about 

Chris

Hi Chris
No argument here! 
ATF, in fact, is not the best fluid in the world, but is the most available and is quite suitable for hydrostatic steering systems. In fact, although it is specifically formulated for automatic transmissions, it is perhaps not even the best for them as it is so "thin" that it doesn't provide maximum protection in terms of wear. In a H/S steering system, however, this is not a problem.
Using universal oils for steering is fine if the SAE rating is sufficient to ensure that the oil has a low enough viscosity to circulate freely, and without placing unnecessary pressure on components such as the relief valve/s, seals and pump. Universals do, however, contain additives that are completely unnecessary for an H/S steering system - such as detergents - and these can harm the system in time...if only by "finding leaks" and affecting seals.
ATF will not damage an engine unless the proportion of ATF exceeds about 25%bv of the sump volume, and even then it is only as you describe; by loosening deposits. Above this concentration, however, you are also seriously reducing the protective quality of the sump lubricant in high-stress areas such as the crank...
The important issue with steering oil is the Viscosity Index, whereby a balance must be struck between steering functionality and protection of components. Low viscosity universal oils will achieve this, but the additives are - at best - useless and/or costly, and - at worst - harmful.