Clutch Transmission Unit Leak

Leaking slave cylinder is a perpetual Ducati issue as are over-tightened bolts which strip threads.

Cure is to completely strip the slave cylinder e.g. actually rake the pistin out and don't just look at the seal, you often can't tell anything from just doing that. What your looking for is any crap, sludge and scoring it may have caused to the actual cylinder itself as the piston pushed in and out. Chain lube and the grit it attracts, make for a great scouring compound that gives the seals a really hard time.

However, regardless of any scoring, change BOTH inner and outer deals anyway. They only cost a few quid.

With regards to the bolt, which is obviously the main issue here, carefully Helicoiling the outer case is the way forward. Kits are about £15 on Ebay.

 

Before Helicoil, see if a 5mm longer bolt with same thread pitch will fit.

 

But the hole may be deeper than the bolt, use a thin nail or welding rod to measure the depth.

 

There is an o-ring around the actual piston and another that fits inside the hollow and of the pistin. The latter has a small hole in the face, into which the clutch push rod fits. This seal just pulls out of the end of the piston.

Oh and if the rubber boot that goes over the top of the piston and push rod assembly is split or perished, replace that too. It exists to help keep crap out of the seals in the first place. Not very effectively obviously!