so does anyone know what the difference between power steering fluid and atf is? besides one being clear and the other being red.
ATF is basically hydraulic fluid, bmw toyota gm use it im sure theres more.

Diffences are in the actual (secret) ingredients. Lots have to do with the seals. The wrong fluid could damage a seal, and cause a leak.

Lubricating properties, etc.

You'll never get an exact answer, due to the 'proprietary' nature of the fluids, and who makes them.

ie: Honda gearbox oil. It pours like 10w-40 motor oil. Honda says NEVER use motor oil in the gearbox, as it does NOT have the (secret) lubricating ingredients.

ah yes gear oil is designed to stay put on parts, where motor oil is designed to shit out. it comes down to different additives in the oils.

Sorry to bump an old thread, but I have figured out that my pump went bad, and I am going to replace it. I found two online (link), and was wondering which one I should use. I don't think I need a new reservoir, but would it be good to replace it anyways? Or should I go to a dealership and order a new pump? Also, do I need to order new hoses at the dealership? Thanks.

Try finding a wrecking yard in your area if the price from the dealer is too high, (which it probably will be) a self service yard is the best cause you can practice on that one before you thrash your own.
Power sterring pumps do not tolerate low fluid situations. I had my return line fixed at a hyd shop and the idiot that was doing the line told me to start it up and I heard a loud squeeling so I shut it off, the hoise happened right away. The dumbo forgot to put fluid in and the pump went in about 2 seconds.
My BMW is supposed to use a special CTF 7 hyd fluid but I also have the hyd suspension which is the same as the system as the power sterring and it also provides the power assist for the brakes. The fluid costs about 8 dollars a quart so I use 10W diesel which works great in the bimmer, and costs about 3.50 a gallon.
Don't fprget to check your hoses that go to the reservoir cause they are probably hard as a rock. As long as your repairing the system you might as well check the rest of it.

You can rebuild your existing pump for about $30 with the Toyota power steering pump seal kit. Dealer have them. This is common on the 3.0 V6 pickups and 4Runners. Not hard to rebuild. Here's a link to the truck i re-sealed. Not the same I'm sure, but pretty damn close.

http://members.cox.net/stacewilliams/ps-pump.htm

oh yeah, Dextron ATF. Same as the 4x4's

Kinda cool really. 1 fluid for PS and Auto trans,
1 fluid for Clutch / brakes.

They don't make a "clutch" fluid, like the PS fluids.. or do they?

I ended up getting a new pump. So, has anyone replaced their P.S. pump before, and if so, any tips or troubles when removing or installing the P.S. pump? Thanks.