This begs the question which fluid and how old is it? Although it’s all rather academic as the damage has happened but, if it were mine, I’d want to understand why it happened so I can avoid a repeat situation. ps. I guess we all probably want to know what caused it.
Last fluid change was October 22. Only thing different to normal use was the heavy traffic getting out of town and it was a warm day. Only time i really use the rear is in traffic/filtering round it.
In just under a year the fluid shouldn’t have wetted out that much but even if it was something like Motul RBF660, when fully saturated, the boiling point is still 204C. Your brake lines are fully clear of the exhaust aren’t they? ie there’s room for air flow across them? and the heat shield wrapper is still in place? If the answer to both those is yes I’d be looking at the calipers and pads (what’s left of them) did you have a seized piston, was it dragging and not returning ? mind you it will be hard to tell now but I’m interested n what you eventually believe to have been the cause.
Yep but even possibly the fronts aren’t tested by a huge load. My BMW RT had an ABS pump failure so had only what BMW laughingly call ‘residual braking’. You have more effective braking putting your feet down. There have been a few instances of riders finding out how‘good’ that is at speed.
Funnily enough it is indeed Motul RBF660 that i use. Brake lines are as they were from the factory, ive not touched them but can see much in the way of heat shielding. Cant see the ABS pump of course as thats hiding under the tank and air box which are a pain to remove without an extra pair of hands for the fuel pipe removal under the tank. Youre right we'll never know on the sticky piston front, they were pretty well stuck but smells like thats the o-rings melted in there, and the big hole in one piston is making it tricky to push back in anyway. On the plus side, meant i could remove the hub and grease it up as it was totally grease-free - 5600 miles only. Tried rotating it to see if i could get at the disc bolts at the end of the eccentricity? You cant. Axel out so figured i might as well check while i'm here.
So after a cheeky 2 week tour of the Pyrenees on the Multi I've sourced and fitted a new disc, calliper and pads then bled, bled, bled, bled on the Monster and today been to bed them in. Seems i have a choice: 1 - no back brake (wont skid on gravel and barely stops itself rolling down the driveway) 2 - binding back brake Seems there's no in-between anymore. M/C next investigation.
