In truth, I have never been fully satisfied with the lever firmness for the front brake on my 2015, 1200 Multi DVT. There has always been a sponginess about it and with a wee bit of effort it could be almost pulled back to the handlebar. Now it has been bled, rebled and rebled again and again in a variety of ways and nothing has solved this. Also, if the bike is left for a day or so the lever will actually go back to the bars ! Then after a few pumps it will gradually gain a degree of firmness but not what I would expect or want. Then again, leave it for 5 or 10 minutes and when you come back to it it is soft again and needs to be repumped. As it has been getting worse recently, it’s time to do something more, to fix it properly. I really am of the opinion that there is no air trapped in there and that there’s a different problem. The bike has 20K miles on it and I am thinking along the lines of rebuilding the master cylinder ??? Would that be a reasonable course of action, would you say???
You could while the system is empty, belt and braces. However, it’s more than likely the master that’s your cause of the trouble.
Give the master cyl bore a polish while you are in there, I like using these pottery sponges in a drill with some Autosol Alu polish. The larger ones work great on clutch slaves too. I have revived a few masters without even replacing the seals this way.
