one of the pistons of my caliper extends much more willingly than the other. The brake wasn't working properly so i re-bled: still not satisfactory. Under lever pumping with the pistons held back the more willing piston squelches out a tiny amount of fluid and i believe is sucking air up into the caliper.
Obviously there is a bad problem with that seal. I'm trying to work out how and why. I have never let the piston protrude more than 2mm when either cleaning (gently with soapy water) or just observing them after bleeding etc. Is that too far? I have let a shop bleed them before (the mechanic was full of chat about how easy shimano brakes are to bleed, it put me off him and it wasn't a good job). I have also got my brakes VERY hot recently on fast mid summer rides.
any diagnoses/help apart from that i don't go out enough and i need to use more upper case letters? should i ring madison?
thanks
The seal has failed. They do. It might be related to the heat but unlikely. sometimes there is no reason. You need a new seal. good luck
where do new seals come from?
please thank you
when a man seal loves a lady seal they do a kind of "special hug".........
have you cleaned the existing piston and seal? strip the caliper and check it's not just dirt ingress as it usually is
hahahaha! LOL (don't usually do 'lols') strip the caliper? what take the piston out and clean the seal? i didn't know you could do that. please can you describe the process you would recommend? many thanks
You can't buy shimano seals, you're supposed to buy a new caliper. You could try sending it to Madison and see if they can fix it. Or try a bearing supplier to see if they have a similar seal.
I have a useless saint brake on a shelf with exactly the same problem
Yep, Shimano even show the caliper as a one piece item on their exploded view, so no chance of spares there. As above, i'd contact Madison's custome care department and get it sent back, their warranty on Shimano stuff is normally very good.
You need to contact the retailer that the caliper came from. If you ring Madison they will point you to the place of purchase.
thanks guys! annoying!