1996 Discovery, 300TDI.

I have been struggling with this for the last 6 weekends and would
appreciate any help/advice.

story so far.

The clutch on the Disco failed whilst driving and it was found to be
the release fork had broken through at the pivot point, took it to a
mate who suggested he also replaced the clutch as it was starting to
show signs of wear.
Got it all back together but couldn't get it to bleed.
Replaced the slave cylinder, still not working, would bleed fine but
then after a few minutes of driving would get air back into the
system.

Found master cylinder was leaking under the reservoir replaced this,
still no joy.
Eventually found a small crack at the end of the clutch pipe by the
damper. Replaced the pipe but still not working.

Finally found the new slave was overshooting its travel and letting
air in past the seals. Reconditioned the old slave and now have the
hydraulics bleed and air-free but still no clutch :(
Pressing the pedal causes it to go straight to the floor and not
return. If I connect a pressure bleeder to the system the clutch works
correctly.

The piston moves fine in the slave.

Have found that when the guy refitted the clutch he didn't refit the
clip that holds the piston rod to the fork, is this going to cause me
a  major problem?

If I move the clutch fork in the bell house it moves freely but there
is no resistance, should there be? How does the slave cylinder get
pushed back in?

My questions are:

Does this sound like a hydraulics issue? or a mechanical clutch issue?
If a mechanical problem is there an easy way to get to the clutch
without dropping the engine/ gearbox out completly?

I have several jacks but no engine hoist.

Taking the vehicle elsewhere is not an option.

Would appreciate any thoughts/suggestions

Ben