The don't want to go into the callipers whereas I can remove and re-fit the old ones fairly easily.

Does this mean that my brake callipers are shot? (pistons buggered) or am i missing out a simple step?!

Cheers

You've pressed the pistons back into the caliper, right?

well, heres the thing.

I assume i did, because once the old pad was loose, i pushed it as hard as i could into the piston with a screwdriver. I didn't feel any movement.

I poked a screwdriver in the hole at the top and tried to push it in that way too.

No movement there either. Am I being a complete retard?

No not really - they have to be forced back quite a lot further than you would expect - put the old ones back in then carefully lever the rear edges back using a long screwdriver against the disc being careful not to damage the disc. Don't rush it and just apply constant pressure and you will feel them go back in....

Thanks, I'll give it another go in the morning. Thanks Nels and Russ!

If you use a screwdriver which is small enough to fit through the gap at the top of the calipers, that usually has much more chance of success than trying to lever the pads from the bulkhead side, since the direction of the 'push' will have better alignment with the cylinder.

As already mentioned, the old pads are the ideal interface between the screwdriver and the pistons...

Sometimes it helps to open the bleed nipple as pushing one piston in pushes out another one . Fit a tube to catch the displaced fluid and top up the resevoir whe done. Pushing in the piston forces the fluid back up through the master thats why it takes ages and is quite difficult.

All done! I managed to find a screwdriver that was a bit skinnier than the one I used before, and managed to push the Pistons back a bit further. I also closed the spring on my thumb which hurt a lot. Thanks for your help everyone.