Chris, I'm fairly sure it was fluid boil. Simply because the very next corner after it happened was after a long straight and I had the brakes return to fully working as soon as I touched them.
Instructor at the track and track tyre guy also thought it was fluid boil
That's not saying it wasn't pad related, but it seemed to fit symptoms more with fluid. Especially as it happened a few times and each time brakes came back as soon as I backed off and they cooled.
The "cause" as such is my riding, or should I say my lack of skill at riding :Pi was way to gentle on the brakes so was lightly braking for much longer than I should.
If I had been more confident I would brake later and harder so on the brakes for less time = less heat build up.
Again the instructors thoughts. My thoughts were more .... Oh shit I'm gunna die.
Lawrence, 5.1 from everything I have read and been told by shops and guys at the track has a higher boil point than 4. But I notice you say high temp 4. I did see mention of this on google and was referred to as race spec dot 4. But there was little info and what there was, was a bit sketchy.
Not seen it widely available either.
Trud, that's my understanding to.