Well I have taken the old ones out easily enough but cannot open the pistons enough to get the new ones in. I know that one can prize open the pistons but in this case they won’t budge anymore.I read that the o ring may have seized but what do you say?
They are avid juicy

I assume your talking about pads?

Try putting the old ones back in if so and using a screw driver too push the pistons back more.

Failing that I’d say the easiest way is too let some fluid out and rebleed when new pads are in.

Yes, do that or throw them away and buy Hope.

Put the pads back in and get a bigger screw driver to prise them apart, they will move eventually.. Watch that your pushing the pistons back in squarely, as they is the only reason I’ve come across that they won’t eventually push back in. Had an almight battle with a hope mini piston back in, the other week, but I won!

PS. as much as I love Hope, shimano’s brakes are pretty awesome at the moment.

Failing that I’d say the easiest way is too let some fluid out and rebleed when new pads are in.

This is what I had to with Avid Juicys. When you push one piston in, does the other move out, so you still can’t get the pads in? If so, that means you need to let some fluid out, whereas if the piston just doesn’t move it may be seized.

ok great thanks
Is it possible to empty a little out via a bleed screw somewhere or do I need a whole bleed kit?

Yes, you can let some out from the bleed screw on the reservoir at the lever, and that will enable you to get the pads in. But you’ll probably need to top them up again after. The best way to do that is with a bleed kit (maybe by taking the lid off the reservoir, if you can get the screws undone?). Epic bleed kit is good and not expensive.

Greybeard – Member
Yes, you can let some out from the bleed screw on the reservoir at the lever, and that will enable you to get the pads in. But you’ll probably need to top them up again after.

Even easier, open caliper bleed screw (probably wont even have to fully remove it), push back pistons, close screw. Had to employ this technique in many race car parks, never had to re-bleed and it’s easier to do as everything’s in one place.

Even easier, open caliper bleed screw (probably wont even have to fully remove it), push back pistons, close screw.

OP, no reason not do this, my suggestion was what I did but legend obviously has more experience of the problem so go with what he says.

+1 for epic bleed kit.
Cheap and great quality. Worked perfectly for me when I had a similar problem.

Let out a little fluid. Push pistons back in. Then rebleed. .