My power steering has been whining a lot lately and the wheel occasionally shudders when I'm parking. I fear that soon the power steering may begin giving out on occasion like on my old pickup, rendering the wagon unparkable. I was reading my service manual looking for instructions on how to rebuild the power steering pump (I might also just buy a new one for a hundred bucks or so depending upon your advice) and I discovered that I'm not using the right fluid. My manual says my car needs type A automatic transmission fluid and on the one instance I needed to top off the fluid I just used STP power steering fluid, it's likely the last couple of owners did the same thing. Does that make a difference? Should I drain my power steering fluid and use type A automatic transmission fluid before I try rebuilding the pump? Is there a bleeder valve or a drain plug or something like that?

 

I'd try using the right fluid BUT at this stage I doubt it will make any difference. And I don't believe there is a drain, just undo a hose and the pump will pump it out... just don't run it dry too much. I'd get a used one from a junkyard... cheap.

 

Pick one up from the junkyard, I think one will run you 15 bucks. I use regular old power steering fluid in my car with no problems.

 

Nah, unlikely to damage anything. The worst you can do with the wrong fluid is cause a few small leaks due to too thin an oil.
It's just a very basic hydraulic system, pump to pressurise fluid and two power chambers plus assiciated return valves. It really doesn't care what sort of fluid is in there, as long as it contains no air or water.
Shuddering is often associted with pressure valve issues, so don't overlook the rack.

Regards, Andrew.