i checked the manual and it only says to inspect the brake fluid. it never says to replace it. i have two bmws which recommend fluid replacement every 2 years, but they use DOT4 brake fluid which supposedly absorbs water faster. i also have a 06 mustang gt which i replaced DOT3 with DOT4 (for some road course days) and i replace that every 2 years.
but our cx-9 i will probably replace it every 5-6 years (if i even keep it that long, just got it). we gave a 2000 cherokee to my wife's dad a few years ago and i just flushed the brake fluid on that for the first time. i thought i could feel a difference and he thought so, too (less spongy, more firm pedal). i would definitely change it in-between 5-10 years.
oh, to answer your question, yes, any DOT3 will do. i'd go with a name brand of course, but you can mix them. if you don't trailer/tow or live in the mountains i wouldn't worry too much.
