As the thread mentions I’ve changed the master cylinder recently - pulled the old one apart and it does show some wear down one side of the bore caused I think by less then a straight push by the pedal link rod. That being said I don’t use the rear brake much so I’m more suspecting the master is faulty, either elipitical or has a defective seal that is allowing air to be drawn in. There’s never been a sign of leaking and Rapido checked the abs pump, all good.
What did help was one of these
http://www.stahlbus.com/products/en/...stem/index.php
Makes filling and bleeding a breeze, still needs the calliper off and inverted. Very easy to get an air free flow and no air gets drawn in
6 weeks on pedal remains good, wheel can be locked/abs triggered
After all that I’m pretty sure the master was faulty from new, there’s been a lot of reports of Multistradas and Pani’s with the same all built around the time, maybe a duff batch. Steve, as yours is the same age as mine it might be the same