[Thassos]

Well here are some pics of my homebrew tool used to get the piston wound back, and some pics of the rear C30 calipers to help anyone else with luck..

Tool was made from some flat bar that came from a roofing tie found at a local builders merchant *ewson if you know them !, the holes in the piston are 6mm dia, so i used some M6 short nuts & bolts, and drilled some holes in the bar spaced around 19-20mm apart. The fit was good and required me to oval one of the holes to get the distance just perfect having the nuts on each side meant i could fit it on the piston then lock the nuts against eachother resulting in something that would take the force needed to turn the piston. You might wonder why i assembled the bolts going the opposite way.. well... as you fit the tool and turn the piston by say 90 degrees the caliper body gets in the way so you then just flip the tool so the other end is now used to turn it another 90deg. Calipers on this C30 were ATE ones, and i used Pagid pads which ive had fairly good experiences with if your not going to use OEM parts.

The pads have a spring piece on each of the pairs, worth remembering that one with the spring goes on the piston side, and the one without on the outer side.. Some ceramic grease on the piston end/pad rear and also on the guides (see green lines on pic1).. and dont forget to refit the long spring clips (in blue pic1) once its all back together..

As others mention you need a 7mm hex/allen tool to unscrew the guide pins (some more red arrows on the 3rd pic) i tend to use a long 10mm hex to 7mm tool and then fit a 10mm ratchet ring spanner over the bit which works well.