I have now restored all the bits from the 1500 Midget donor. Good grief, I have never seen anything so rusted. The pistons were seized solid and eventually came out with a lot of heat and brute force. Useless of course by then, so I have new ones now. The odd thing is that they had been fitted with the hollow side inwards, towards the disc, whereas the exploded diagram shows them the other way round. Which is correct, or doesn't it matter?
Sombody had assembled the calipers with bolts that were too short so the threads were horribly corroded. In fact all bolt holes were corroded, so a further GBP50 went on new taps to clean the threads.
I had all the parts blasted and some of them powder coated - the dust shields, the stub axles, and a spare pedal box which will look far better that the one I have. Needless to say in the process some inexpert masking ensured that the threads were plastic coated so again the taps came in handy. The worst part was getting the plastic off the kingpin bushes.
After blasting the discs, it was clear that one of them had been skimmed too much in the past. The other was OK, but it's madness to replace one disc so I have a pair of new ones. They were so cheap that it's not worth not doing. I toyed with drilled and grooved items but baulked at 6 times the price.
At the same time I have obtained the 1500 rear drum units and the backplates have also been powder coated. New cylinders were again cheap on eBay, but the circlips that came with them are useless - very thick and brittle so they are impossible to fit and one of them broke in the attempt. The old circlips were far better, but of course terribly rusted.
Sadly the suspension wishbones were pretty mangled, presumably by whoever pulled the units off the donor car, so I will use my existing ones. Hopefully I can get them off, blasted and powder coated (along with the springs and anti-roll bar) without too much delay. The Midget kit came with good fulcrum pins which may come in handy. The kingpin journals are quite corroded, but amazingly there is no play when assembled so I will quietly forget about that. I had this problem with the existing kingpins and had one of them welded up and machined back to correct dimension, then heat treated to restore strength. It would be nice if there were a Speedi-Sleeve of the right size but I could not find one (and they are very expensive).
1959 Sprite restored at last - after 15 years!