I’ve been having a frustrating time with my rear disc brake (Shimano BR-R785) on my CX bike lately. Running fine for a couple of years but really starting to have issues with it this year. Basically when I put in a fresh set of pads (resin or sintered) it’ll work great for maybe 3 weeks before fading to almost nothing (strangely they actually work better in the wet when they get into this state). I’ve tried bleeding the line, cleaned rotors with isopropyl alcohol, I thought the pads might be a bit glazed so sanded them back, I even changed the caliper a while back. No real improvements. Also seems odd that the front is and always has been working perfectly.
Anyone else experience similar issues or have a fix, something else I can try?