Originally Posted by
dsbrantjr
Unfortunately the rubber seal is not a plain round O-ring; it has a square cross-section which provides the pad retraction function so you can't replace it with a round one or the pads will drag. I suspect Shimano doesn't stock parts for their brakes partly out of product liability concerns.
hi my breaks have gone limp and squeezed all the oil over my discs n pads, I’ve stripped them down and found round seals. I need a replacement what should I do. I believe these have this problem a lot so would like to try a seal with square cross section. Know where I can find any with 14mm internal dia and piston is 17mm. Starting to loose faith in these. What you thinks best.