I searched all of 5 minutes and gave up. My power steering pump is moaning and groaning, has been for 2 months since I bought the car (86 300E). I went to check the fluid level and the tank looks half full, but there is no indicator marks as to whether it is full or not. Is it full?

Also, which fluid should I put in? I ask this because Volvo recommends that I use a certain brake fluid in my 86 245.
Thanks
Joe