250-500cc Rear brake locked up andcocked the braided line today

Last mile of riding my 300 seemed down on power. Ride up trailer ramp at end of ride and notice rear line is smoking. So start to lean in and the thing burst broiling brake fluid everywhere. missed my face my an inch. Sheesh. All my years of riding this has never happened. Any suggestions what happened? I will buy new braided line, new brake pads but am wondering if needing a caliper rebuild kit. Do they make them? If so will do it for front too.

Only thing to know about my rear brakes is rear pads where almost border line metal on metal. I figured one more ride and that was it. Could that have done it(yes I know I know i didnt intend to let it go that far but....)?

I forgot to mention I actually do use that motul stuff. Been about a year since last changing of fluids though. Hasn't mattered in the past?

You almost ended up like the guy in your avatar

wouldnt be first time-lol

i reckon less pad equals more fluid being used to fill pot & actuate piston meaning gets hotter. pistons may have stuck from being too far out or possible dragging? did you adjust freeplay recently when brakes were cold? i had it happen on my front brake, was sweet in garage & around street but under heavy braking there wasnt enough freeplay & it locked on! haha my brother was riding it at the time & nearly went over the bars-lucky! disc was blue hot! had to crack banjo to release some pressure. come to think of it ive had it happen on rear too, i just like minimal freeplay & powerful brakes. allow extra for expansion when hot is the moral of the story i guess. check ya disc thickness too as that wont help if theyre too thin, theyll get hotter quicker & tranfer heat to pads/fluid. ps nice work on blowing a ss braided line man-WOW

I had the same on my SMR449 not enough free play on pedal locked up on me at 90km/hr. All I did was change pads and fluid. Rotor wasn't warped so all good.

Sounds like you had no room for expansion, or something was stuck.