I wonder if anyone can identify what’s wrong with my disc brake?

The piston on which the pad sits was not releasing so I tried pushing them apart with a screwdriver, they were very stiff to move, but since done the brake lever has gone slack as if the fluid has gone and the piston is no longer closing in. There are no leaks so I’m not sure what’s happened. Brakes are Hayes nines.

Bleed them, they’ll be fine.
Make sure the pistons are free to move though.

As Luke suggested.. you need to address the sticky piston first. Once they’re moving freely then move on to a full bleed of the system. Good luck!

Get the epic Bleed system over the Hayes oem one. I needed one urgently last week and couldn’t wait for delivery (like a impatient idiot) and bought the oem one for roughly the same money. I had problems bleeding it the instructed way as I couldn’t squeeze any fluid up from the bottom (yes the nipple was open) and squeezed that hard the bottle popped apart.

So I had to do it reversed and it was Ok to star with I had a full lever. Went to cannock to test it out a few days later and within 2 mins the lever came back to the bars and I rode with only the front brake. 🙁

Major regrets not going for the epic kit but when I ditch the Hayes dynos that I got I will go for a epic kit as it looks much better quality.