Cinquecento/Seicento Fully rebuilding uno turbo rear calipers (should be the same for GT) Pt.1

Next I decided to strip the piston.
remove the circlip (I used a very small screwdriver that fitted in the circlip hole, actually easier then farting about with circlip pliers)

once the clip is out, carefully pull the threaded part (best not do it my way as any damage to the internal thread would be the end of the caliper)

Break down of the piston. the large internally threaded part has a seal on the end which you replace with a new one

I used valve cutting paste to reseat this part into the taper seat in the piston is it was a bit pitted. also check the hole that can be found in the ridge near the end of the piston is not blocked (both of mine where)