Its where the pins go into the piston. tighten back with a plate to the edge of the caliper then twist the handle to wind back in. ( Great description - just presume standard tool)What type of wind back tool are you using? The attachment i use does a push and twist have done my rears twice and both times were fine.
could try putting it back together with the old pads and discs, press the brake to push the piston back out then go at it again. and see if it's any better.
What are the piston seals like? if split perhaps there is corrosion somewhere.
And I'm sure you are but you're doing it with the reservoir cap off aren't you?
So with getting the piston out do i still need to turn it the opposite way ( anti clockwise) after pressing the brake and it will come out to be able to clean ?rear piston just turns in whilst under a bit of pressure, if it won't go, the caliper seal will have corrosion behind causing it to grab the piston, it might well be in good shape still and can carefully be prised out, recess scraped clean and cleaned seal refitted, bled, and off you go again or buy a service kit with a new seal etc. To get the piston completely out just press the brake a couple of times and clamp the flexi to save fluid after, it won't lose much. Getting the dust boot back in is fiddly, easy enough to do for a novice if careful.
breaker bar on wheel bolts isn't uncommon, same with disc bolt seizure really.
Thanks for the comment. I take it all gen 1 have same rear calipers ?I had a broken dust seal on one of my rear callipers and it had been that way for a while. Worked Ok but I couldn't easily turn it in to fit new pads without getting it stuck.
I fitted a new calliper rather than spending hours trying/hoping to fix it.
No they don't. Pre mid 2003 cars have a banjo connector. After then its a straight screw in. Easy to see which your car has by looking behind from the rear of the car.Thanks for the comment. I take it all gen 1 have same rear calipers ?