I have used the Prestone equivalent on several Hyundai cars/trucks with no bad side affects.

It is often rotted metal lines in the salt use areas that are the first problems for power hydraulic steering.

But changing out dirty fluid still a good idea. Basic power steering fluid is semi synthetic hydraulic oil, this is just a few more additives, rubber seal rejuvenators etc.

 

I wouldn't use a fluid with stop leak. If you have a leak find the cause of the problem and if no leak use regular fluid.

 

Yes. Think of it like this; stop leak is just a bunch of goop that is supposed to plug up leaks. Guess what? It's going to plug up everything else too. Never put any "stop leak" type product in anything. It will clog your radiator and heater core, it will cause imbalance in your tires, it will gum up the internals of your P/S pump. Someguy is 100% correct, instead of trying to fix a leak by plugging it up, fix the broken part that's leaking.