Clutch works for a while then gets progressively worse , as in no clutch at all.Cant find any leaks , have changed master out, has anybody tried to change the slave cyclinder mounted on the gearbox casting.If so what are the procedures?

Is it mounted on the casing and not an internal concentric one? I thought all 6 speed gearboxes had a concentric slave cylinder.

 

Your description of the symptoms and no leaks is consistent with an internal concentric cylinder, if its the external mounted one then you use your eyes, if you really need procedures then you are not up to doing the simple job but if you have already changed the master cylinder which is really difficult then you must be.

 

Perhaps you are confusing the bleed block AKA clutch peak torque limiter with the cylinder?

 

How did you bleed the clutch after replacing the master cylinder?

Hi I bleed the clutch with a vacum at the end of the line to the slave, and it worked great.There is a valve externally that can be used as well to bleed.Im wondering if the internal parts of the slave are worn? I did take out the starter motor to see if I could access the slave, but no.I did see on a forum that the 5 speed manual has an external slave which sounds way more  mechanic friendley than this arrangement.So to summarise. I still have a very intermittent clutch , once its blleed , its good, then over a few days it loses all it function,? Any suggestions would be appreciated, 

Bleed through gravity and not with a vacuum or pressure bleeder and always bleed only from the thumbturn valve for the purpose, this is because directly underneath it is a void to catch any air that is pushed down through the system or draw in through the O ring joint between the 2 parts of the concentric slave cylinder, the air chamber void is also present on the external slave cylinder, it forms part of the bleed block.

 

Bleeding of air collected their takes a few seconds, just open the valve and watch the air bubbles come out (into a vertical clear bleed tube) and close it when they cease, you dont even lose any measurable amount of fluid so no need to top up the reservoir.

You will need to replace the slave cylinder unless you find by sight or feel that you can get to the joint in the plastic feed pipe through the starter motor aperture, air will be being draw in through the O ring.

 

It was only after I removed my transmission to replace mine that I forensically found the cause and pondered on whether it would have been possible to replace the O ring through the starter motor aperture.