An m8000 brake on my bike has suddenly started behaving very oddly. When braking hard, I get about 2 seconds of normal braking, then it fades and the lever pulls to the bar. Here’s the strange thing, if I let go and then pull the lever again immediately, I get full force braking again followed by the date again 2 seconds later.

I’ve bled the brake and the fluid was lovely and pink with no air bubbles. The brake has been fantastic for the full year I’ve had it up until now.

Any thoughts?

Send it back for a replacement under guarantee. It’s broken.

They all do that sir.

No they don’t. I’ve got 2 pairs on different bikes – both bang on. One pair went back under warranty as they were early ones affected by a batch issue. Replacements have been perfect, as have the other pair.

Sounds like the seal in the lever has failed – warranty job.

Cheers for the advice. CRC contacted and awaiting the results.

Typical symptoms of air in system.

No indication that they’re broke.

And no, they don’t all do that

Its not air in the system – that would not led to these symptoms. Its a failed master cylinder seal