Rear brake bleeding

Hi everyone, sorry to do this with my first post, but here goes:

I recently changed the rear caliper (2000 model), and there's now a load of air in the system that no amount of bleeding seems to shift. The fluid coming out is clearly new fresh stuff, no bubbles, and nothing's bubbling up in the master cylinder. There's no sign of leakage anywhere.

I know there would have been a lot of air in there before I started - The trouble started with a stiff pedal, which became a suck pedal, which then bound at speed and ignited the pads. While freeing the pedal up I ruptured the (presumably heat damaged) seals on the old caliper, and drew a lot of air in. Could it be somewhere that can't be bled, like the piston on the pedal?

Thanks for any help or advice

Welcome in mate!
Did you press the piston all the way into the caliper before bleeding?
I can only think that the seals have started to fail in the master cylinder; it's pretty easy to bleed the brakes on the cb if the seals are all good.