I have removed the drum from my drum brakes, but the rubber from the actuator has unsealed itself as can be seen. It is pink in colour. What have I done wrong and how can it be eradicated?

Many thanks
Rescued attachment WHY HAS THIS HAPPENED TO THE CALIPER.jpg

Not a good pic, but if I'm seeing it right just clip the rubber back over the cylinder & gently squeeze the shoes down to push the piston back in enabling you to get the drum back on.

Just looks like its popped the pison out gently squeeze back in and should be okay

was it like this before you took the drum of though? if not, then push it back in as said, but if it was like that inside the drum, it needs more fixing!

Poor picture but looks like the other end has'nt moved. So all movement has come from one end. Take off the shoes and check that if you push in the piston at one end the other moves out by the same distance. Careful push to quickly and it will pop out the other end.....

If the other end doesn;t move suggest cyclinder is siezed.