MAgura brake master cylinder

On a three days ride my front Magura master cylinder died: it was stange for some time: soft, hard then mushy then rock hard etc. It locked my front wheel but I was able to let some brake fluid out and finish the ride with only my rear brake (with a Yamaha R6 caliper tahnks God!). I am looking for a rebuilding kit but cannot remember the size of the piston... What the best size for a stock Norton caliper? (maybe I'll buy a new one, this one is 10 years old and has to use a BMW /2 brake switch!)
Thanks
Philippe

Check with Stan www.rockypointcycle.com He'll mostly help you with the old one but if not possible, he has the best price on new ones!

http://www.rockypointcycle.com/Merchant ... y_Code=N11