i've rebuilt the slave, replace the plunger on the MC, and still having issues with this.
oil just starts appearing near the lever bolt / sleeve.
i ride for about 3 hours and then start to lose the lever, and open up the MC and there is nothing in the resevoir.
i've now gone ahead a purchased a replacement Magura MC, but not convinced that's going to do anything either...making riding my 570FE virtually impossible and not at all confidence inspiring.