It uses ATF. Automatic transmission fluid.
I'll bet it was never serviced. Sad.
m5board dot com, much written about this. You have multiple hoses that can leak- low pressure (cheap) and high pressure ($$$)...oh, and if you are lucky like me a pump which grenaded and cost $400, plus $400 for hoses, a new reservour, and a very messy 3 hours.
At the very least, find out what is leaking, Buy the part and replace it, get as much old fluid out as you can, then add fluid, run and top off. I had so much metal in my system (ie the only part that wasnt replaced was the steering biox) that I had to run a few quarts through to flush the debris properly...
Keep it as simple as possible...but no simpler.