I see you're in canada. Any regular fluid is fine, but GM cold climate power steering fluid might be best if you're starting the car below -5C.

I'm currently running ATF DEX Merc3 in mine, for what it's worth.

 

The book clearly warns not to use trans fluid in Saginaw pumps, but I digress.

 

@1slow96 any reason given? Chrysler uses ATF in theirs. I got the car with ATF already in the system. I am about to rebuild the box here soon, so if it eats seals, I'll change.

 

My theories? Transmission fluid includes friction modifiers for clutches/steels. Power steering fluid would have no need for them, and include additional lubrication for the metal-to-metal operation of these pumps. Years ago trans fluid was used interchangeably. I would use it in an emergency, but P/S fluid is widely available. Most systems don't require much fluid anyway. I had been using Red-Line P/S fluid until LEE rebuilt my pump, and steering box. They said not to use synthetics. Did I listen? Of course not. Eventually, I changed over to AC Delco fluid, and noticed a difference. Smooth, and quieter operation. I suspect that LEE tightens the tolerances to improve performance, leaving less margin for error.

 

I will vote with 1slow96.
It is all about the additive package and base oil.

At one time all of the "big 3" suggested a specific "power steering fluid" and ATF.

As time progressed I guess the parts changed or the "big 3" found that the car's power steering would exceed warranty time on ATF .

If the PS pump had a specific fluid on older applications and just changed to ATF after a certain date I use the older specific fluid.

 

As trans. fluid becomes more specialized for modern transmissions. I suppose it gets further away from what is ideal for these pumps. Especially considering they were only made for a few years. Discount part store re-mans flat out suck. The best replacements I've found are gently used OG pumps from Caprice/Roadmasters. Then replace the seals o-rings with a $10 AC Delco rebuild kit.

 

 

Thanks for the info

I'll just look for anything that says Power Steering fluid then. Yes it's cold in Vancouver BC right now. It's supposed to drop to around -10 Centigrade tommorow (about 20 Fahrenheit).

I wish I knew exactly what the user manual says (I can't find mine temporarily). The Haynes manual (I found that one) doesn't mention fluid type).

 

AC Delco offers a cold climate fluid that should be available at GM dealers

 

This is what Lee power steering recommended for the box I have installed from them.

 

1996 Caprice Owners Manual Maintenance Part D:
GM power steering fluid 1052884 pt or 1050017 qt

 

Nice video! I may be wrong, but every automatic transmission i have ever had the pleasure of working on had a pump inside of it, and if memory serves me correctly they were all METAL TO METAL. Depending on how bad the leak is, how often you have to add fluid, atf should be fine, hydraulic fluid, Tractor hydraulic oil from tractor supply would also work, when you fix it get the expensive stuff

 

And, they all have friction materials, clutch plates,etc. that power steering systems do not.
The service manual specifically states not to use transmission fluid in Saginaw pumps.
Power steering fluid is no more expensive than transmission fluid. Why wouldn't one use it?