Hayabusa Clutch slips when going down the road.


My 01 Hayabusa was purchased with a clutch problem. I saw the clutch fluid was red brown very bad and the slave cylinder was destroyed due to the rust. I cleaned the system, put new dot 4 fluid to the system and it worked. for a little bit and it went back to its original state SLIPPiNG again!!!!! The problem is the fluid is not going back or the slave cylinder all the way. its hanging not letting the clutch pack to the engage position. theres pressure when I release the bleeder, and I get clutch once again. were can the problem be? Need help im frustrated.
Not a mechanic but it sounds like you need to rebuild the slave, at the very least clean it up real good.