i have a similar problem aswell...i have a toyota corrola ..the level of power steering fluid tends to drop really quickly and after that my power steering belt also starts making a very loud noise..once i fill it up again..this sounds stops...
but the things is, ive noticed that the fluid is infact leaking..i got it checked from a mechanic near my place and he said the same thing...can any one of u in karachi tell me the name of a good mechanic who can fix this problem because my mechanic was saying that ud have to take ur car to tariq road or someplace to get this fixed..i have no clue