I've been running Shimano Deore 525 brakes for about 4 years now. The back brake is pretty much refusing to cooperate. I've bled and bled and bled again but in order to get reasonable performance it really is a case of grabbing a fistful of lever rather than my preferred one finger technique. There are no leaks, I've tried new pads and the rotors are spotless.

Will new hoses make a difference or is it time to sell and replace?

Any advice appreciated. Thanks.

Sticky piston?

The piston on mine stuck a couple of years back. IIRC I just cleaned it up and lubed it. 10 minute job. No problems since.

I've heard of people having problems bleeding some brakes because the design of the caliper means air frequently gets trapped in crevasses.

Hmmm, air is a possibility I suppose. Best get some more fluid and bleed again.

Don't risk your brakes or your life!