I re-fitted the brake calliper only to find that the wheel wouldn’t rotate again due to a pads being a tight fit. This sounded familiar http://campervanman.blogspot.com/2008/06/finally-got-round-tuit.html .
I measured the wire wheel brake disc and found it was 0.3mm fatter than the steel wheel one just removed. So this time I removed the sticky pad behind the pads and gave them a polish on a bed of sandpaper to shave a few microns off the pad surface.
This seemed to do the trick until the caliper bolts were fully tightened. The discs stopped spinning again. This time due to the calliper bolt. Over the years I’ve lost assorted bits but this time I was missing a spring washer – or was I missing something else.
Hanging on the wall were a few bits I’ve painted but forgotten what they were. I had three of these brake things (hose bracket) one was slightly different. One style goes under the bolt the other goes on the bolt extensions. It seems it changed during production. To solve my problem I fitted one odd one under the bolt with a lock tab. Wheel now spins.
Snag was I had to move the banjo brake hose slightly. It didn’t seem to tighten up afterwards. I had stripped the threads of the banjo bolt!
Looking closely I found that the new aeroquip hose banjo was slightly thicker than the original so less thread was available to grip.
So I need a new longer banjo bolt and probably a repair to the brake calliper.
Probably a good job it happened now as it could have come apart on the road.
Maybe I should have converted to dual circuit brakes after all.