I am guessing an Air lock. (Bubble) in line from last time you flushed system. It can stay in there forever if not flushed completly.
Happens to my 09 rocker heaps
That statement brings me back to the 1st time I rode a Harley bloodog.
These fucking things don't stop real well lol.
Say you got a bit of air in there binnsy.
Took the fatty for a spin today, first time its been out for a couple of months. Up to the first corner and wanted some rear brake, there was none !! Started to head for home to check it out and after trying again a couple of times the pedal came back good as gold. Got home, checked fluid, which gets flushed every year and was full as a boot. Took it out for a ride again without any adjustments at all and was as good as gold.
I tried this and it worked then the problem came back give this a go
binnsy, that's no good, wondering why u flush it every year? I only ever bleed my brakes when I change the pads it it feels like it needs it. I always make sure bleed nipple in highest spot so air can get out.