83 320i manual questions

Hello to all I have a 83 BMW 320i manual and have some questions and was wondering if anyone could help me thanks in advance. The problem I am having now is my clutch pedal is stuck in the half way position and won't let me push it down all the way. In other words the clutch won't engage down all the way to shift gears it appears to be stuck in between. I can still depress the clutch in and out fine however it seems to be in the half way position. Can you please advise me if this could be air in the line doing this is that possible? 2nd question then is if it is not air in the line then I am guessing that my clutch slave cylinder is going bad and needs replacing correct? Please advise me as to what else this could be and what would be the best fix? Thanks very much for you help in with my questions.
Dave

Rebuild master and slave cylinders. Flush the lines and bleed the system. Set the pedal height as per book. If it still plays up have a friend check the flexible for swelling when pressure is applied. If that lot does not work it sounds like a mechanical problem in the bell housing (bent clutch fork?) or the clutch itself has died. Gearbox out. May as well pull engine as well and tidy up the engine bay - could even freshen up the motor with oil seals plus big ends and mains.

I had a similar experience in my 81 323i, on my car it was the clutch slave cylander. The pushrod was able to deflect at a 60 degree angle, of you pull the slave cylander out (you don't even have to disconnect the line if your careful) you can check to see how much play the pushrod has. In my case I removed it and the rod fell out of the slave cylander.
I'm not saying this is your problem but it sounds very similar and it's easy to check.
Best of luck.