Modern Vespa

Right put new rear pads in BUT when i tighten the calliper bolts, it locks the brake disc. can't move it, undo the bolts and it moves again.

pistons are as back as they can go

thanks

Reservoir over full? Excess fluid can keep pucks from retracting fully.

Thanks, cap is off, so should just overlow, think pistons are back as far as they go (but can't be, so will have another go to see if i can get them back further).

then if still fails, then pads have to be wrong, ? to thick, but cant be as fit in calliper fine.

can only be, pads, or pistons not fully in ??

Only thing I can think of is if the your piston is not sitting flush. This locked our wheel when we did our pads.

Yes, thanks, they look flush and feel flush, i have put the calliper back on with a couple of washers between calliper and bracket and lightly done up the boys, think once ceded in, it may settle and i'l tighten the bolts up as it goes.

thanks for your help, checked every thing

Just an FYI brake fluid will eat though your plastics & paint. Don't let it spill anywhere.

well, we put extra washer in-between the calliper and bracket, got it to work, put wheel on, tightened up wheel bolts, that pulled the pads back on, left wheel on, manipulated the washers out re tightened calliper BINGO all works as should. the only thing we could think was a pad must have not seated properly, by 0.1 of a mm.

Well don't fancy doing all that again,

Thanks for all your suggestions and help