Juvecu

Just an update for the curious people who are wondering how this ended. I ordered new brake pads and seals. Took everything apart again, polished the pistons, put the seals in and then the pistons. The pistons were moving a lot easier after that (I could easily move them by hand.) The new pads were still getting stuck on the shims so I took the shims off and noticed corrosion built up behind them so cleaned the corrosion off with some sandpaper and put the shims back on. The pads could now move freely and had a bit of room spare for movement. I put it all together, fitted it back on the bike, bled the brakes and it's as good as new again. Lessons learned: - always replace the seals if they look a bit hard - check for corrosion behind the brake pad shims if the pads get stuck on the shims Thanks for the advice, hope this helps someone in the future

The pads have some life left in them still, ~2mm (service manual says 0.8mm is the limit.) I didn't remove the shims so they are still the way around that I found them. That doesn't mean that the previous person didn't fit them the wrong way around (they look as if they would work both ways around, only way to find out is to swap them ) I'll stick some copper grease on it too, should have time for this today.

The pads don't let go of the disk enough to let the wheel move as free as it should. They seem to be stuck on the shims as opposed to behind held there by the pistons. Copper grease seems like something I could try, I think I have a tube lying around the garage somewhere...

I've changed the brake fluid, I think I'll probably change the seals while I have it off. Just wondering about the binding between the shims and the pads, does anyone know how to get hold of the shims, do they sell separate or do you have to buy some kit?

I cleaned all the dust out so I can rule that out as a problem. It has 2 pistons, one is a little smaller in diameter than the other. I guess it is possible to have brake pads that are so badly manufactured that they don't fit like they should?

I have a 1998 Yamaha SR125 Custom that just failed MOT (roadworthy test) because the front brakes are binding. The front calliper was extremely dirty, I removed it, disassembled it, cleaned it well and put it back together. The brake pads are getting stuck to the metal shims each side and this seems to be the cause of the trouble. From memory I recall that brake pads normally move easily and that the fit isn't particularly tight where the shims are. The shims aren't bent/warped/damaged/badly worn at all, in fact, they look like they are in fairly good condition. I spent 30 minutes searching the internet and I haven't been able to find a place that I can buy the shims from. The question I'm faced with is whether replacing only the brake pads is likely to resolve the issue or not? I'd appreciate any input from anyone familiar with these things.