Master Cyliner 156
I finally completed changing of the master cylinder on the 156 jtd 10v. It only took me 15 hrs!
Knowing what I know now, I would no longer recommend taking out the old master cylinder but instead simply take out the piston and put in the new one from the new master cylinder. This is because when these fail it is mainly the seals, not the unit as such. I realised this as the replacement I bought from Autolusso was good but... the banjo would not screw into the back of the master cylinder.
After doing some checking (although I could be wrong) I think the original is 12.5mm but the back of my new cylinder is 12mm. In the end I simply swapped the piston units therefore using the old barrel and then managed to fit it within 20 mins. I cleaned it thoroughly with clean brake fluid and a very fine sandpaper to take out the rough surfaces in there. Not too much though as it would score it and render the new piston useless as the sealing would be poor and it would simply leak again.
I realised this would be better as when I fitted the the unit I pulled the piston too hard and burst the circlip, thus rendering it useless. I had two choices, take it out, refit the piston and then put back in the car OR try and fit the piston whilst in situ. I replaced the piston within 15 mins and had it all fitted within another 15 mins. If I had realised this I would NEVER have bothered taking out master cylinder and simply replaced the piston.
One last point. I don't apportion any blame to Autolusso as they were very good with the initial supply of the part as they did check it against the chassis no. and were very helpful. I would definitely recommend them and Pro Alfa who gave me some good advice on bleeding it and support if I couldn't get it fitted ! What a difference it has made to the clutch feel too. A FANTASTIC action.