Power Steering and ATF--Are they really the same?
This came up in an earlier post in the 92-99 forum.
It seems like an area up for debate.
It seems like an old school thing to use ATF in you PS Reservoir. I know of a few vehicles that actually called for ATF in the PS reservoir. But I think those pumps and equipment were designed specifically for ATF.
Ours Arn't. I don't feel that they're interchangable. It has long been my understanding that, while many people claim ATF is appropriate for use in the power steering system, it is not meant to be there. While both fluids are mineral oil based, the additives (anti-foaming agents, anti-oxidants, swell agents, etc.) really make a difference. Topping off a low PS system with ATF won't hurt, but at some point the concentration of PS fluid will drop too low (if you keep topping off).
I've concluded that ATF will cause the PS system to overheat, cook the neoprene o-rings thus leading to leaks, and cause the power steering pump to wear out prematurely due to abnormal heat expansion of the moving parts. Power steering fluid, on the other hand, is designed to absorb and carry less heat, thus protecting those parts in systems that were designed for that product.
This is all just my opinion of course. There are arguements for both sides all over the web. Please share all of your thoughts.