I chipped avid juicy 3 piston center changing the pads and the center fell out the pads clipped in nice in the end. Will the pads fall out with out the center or will the clip keep it in place for ever if not where can i get a new piston for it as chain reaction do a piston for jucy 5/7 kit thanks for you help in advance

If you've still got the central bit of the piston you can stick it back on with super glue – I did and it's held for the past year or so. I have since vowed to remain calm whilst changing the pads in avid juicy brakes!

ok i do that seem ok with out it but would be happy if i stuck it back in (note to self must remain calm when working on avid breaks )

The retention clip/spring on the back will hold the pads in
But if you'd ditched it in the first place, pad changing would have been a doddle

If you've still got it, clean up the surfaces and make a good job at supergluing it back on. Then ditch the retention clip on the back. I've not used them for a few years now. The spider/spring between the pads has held the pads against the piston centre just fine