1994 Clutch

[KBTG#33]

I just purchased and installed a clutch kit for my 1994 Z24 cavalier and when i went to bleed the clutch to get pressure built up it would build up a little pressure but not enough to take it out of gear when i asked an area mechanic he said that the the o-ring by the black sleeve coming out needed replaced how do i replace this because i dont even see the o-ring