not much then, i would say that it is the fluid if the fluid levels are fine.....
green fluid isnt the best stuff, try some type of clearer fluid and a higher DOT rating, eg castrol Dot 4 super stop brake fluid, is what i use.
after that i would say that it will be an engine gearbox out affair, but if you do this, make sure you do other things at the same time... like if you car is around 100,000km's and hasnt had the timing chain or belt done, get it done then, and if you want cams and cam gears done. and also internal engine work.
coz trust me, it gets pricey to do all this, considering mech's charge about $65 an hour times 8 hours to get it all out then put it back in for 8 hours.... so just in and out will cost $1040, which doesnt sound good at the best of times