i just dropped a new clutch into my car. everything works well but my slave cylinder for it. ive gone through 2 of them so far. 2 burst the seals and fluid leaked everywhere.... im on my 3rd

i bled the whole system both parts. but i looked online and people were having problems with the second line. so i dropped it out. so i just have the master clyinder going straight to the slave. i bled that again to make sure there was no air in it. but when i pumped it around 3 times the piston from the slave cylinder keeps popping out! everytime. so now its stuck against the yolk that goes into the transmission right now. so right now its stuck in 1st gear or nuetral. one of the 2. when i try driving it, the clutch pedal gets stuck to the floor and wont pop back up. so its in my garage right now and i need info and help. but my whole problem is that the slave cylinder wont go back into the part that it comes out of. it comes out and stays out.... i bought it saturday and put it in after the new clutch went in. any help would be greatly appreciated.
Jeff