After getting the rear axle back together, I went for a quick drive around the block yesterday evening and all was well, so I went for a longer test this morning...
After 10 miles I exited the dual carriageway, as I came to the junction end of the slip road I pressed the middle pedal and my right foot sank right to the floor. I felt surprisingly calm and pumped the pedal a few times to come to a stop. Fortunately my car has lots of engine braking! To cut a long story short I must have put one of the rear pads back in the caliper badly. The pad fell out and the piston got pumped out to the disc, popped its seal and pissed fluid everywhere every time I pushed the brake. I had just managed to clamp the hose to try and limp home when the low-loader arrived.
I've lost count of the number of times I've meddled with brake drums, calipers, hoses, fluid,discs and pads on loads of cars and this is the first time I've made a mistake, I'll be checking and double-checking them in future.
The piston will certainly have scored the disc, how much disc and piston damage means I can't re-use them? Perhaps I'll be able to get the disc skimmed?
I've lost count of the number of times I've removed and replaced pads, calipers, hoses