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Hello
I'm replacing disc brake pads for the first time ... well, trying to.
The brakes are Shimano road discs RS505. I've removed the old pads ok, but I cannot seem to push the pistons back in far enough. This means that when I put in the new pads they are pressed together. I might be able to force the rotor between them, but there's no way it would turn.
So what am I missing? The instructions I used said 'gently' push the pistons in. I've certainly moved past 'gentle' but I don't want to use too much force. Is there some way to get the pistons further in without damaging them?
All help gratefully received.
I’d out the old pads back in and then lever them apart (pushing the pistons back in) with a plastic tyre lever. The pistons aren’t metal (they look white in mine) so be careful not to crack them!
If that don't work ^ there might be too much fluid in the system so you might need to let a little out maybe?
As above, put the old pads back in and use a flat screwdriver or something to lever them apart. But, before you do that, clean the pistons with a toothbrush and some hot water, let them dry, then apply a few drops of brake fluid to the pistons. This will lubricate the seals as you push the pistons in. After you've pushed the pistons in, make sure you clean any brake fluid up before you put the new pads in.
Brake fluid on Shimano....?
Nice one, thanks. I used a screwdriver rather than a tyre lever as the pads were so close together, but I hardly had to use any force. Great tip, cheers.
@hols2
I wish I’d seen your advice before I put the pads in. Next time then, thanks.
And thanks for other suggestions.
Brake fluid on Shimano….?
Obviously, you need to use the appropriate fluid for the brake system. For Shimano brakes, that would be the same mineral based fluid that you fill the system with, not DOT fluid.