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So I now have new caliper piston seals for my RX4 brakes that seem to have a leak from 1 or 2 pistons. I have bore cap tools.
I’ve pumped the inner pistons out as much as possible with the brake lever (holding outer ones in with a tyre lever). Can’t get either to pop out like that though. So removed from the bike and using a track pump I’ve blasted air in and one inner piston has popped out. The other is just over half out - but how do I get this fully out?
I can’t get a grip with a plastic tyre lever and nervous to use anything metal that could scratch the piston….
The outers will be fine with the bore caps removed but need this other inner one out first.
Any tips appreciated
Change the seal in the one that's already out first and re fit that piston.
Then hold all three pistons in and pump the other rear one out.
Could you wrap a bit of old inner tube or like around it and use pliers/grips?
My hope v4 pistons popped out pretty easy doing what you originally done
Seal the other bore so you can pump the second out. But of innertube, a flat surface and a clamp.
Though what SSS suggests sounds better.
That’s a good idea - I’ll have a go at changing the seal on the one that’s out then pushing it back in and have another go with the pump 👌
Thanks
Nope, failed to make anything worse and realised the pistons are only £5.50 each at CRC so butchered the remaining inner one out with needle nose pliers 🥴
Other 3 pistons are fine, old seals out and new ones in. Should have the new piston Friday and then have it all refitted on the bike ready for bleeding. Fingers crossed that solves my leak problem and both Hope brakes are then back to epic power.