rum4mo

The type you are looking for are "right hand" - the issue with cars that have handbrake mechanism built into the rear callipers is, the piston gets adjusted automatically each time you apply the handbrake (if extra wear in the rear pads requires this), this adjustment is done by rotating the piston.
 
So, after maybe 4 years of service life, these pistons have gone through a few complete rotations, when you remove the old pads with worn thin friction material, and replace them with new pads with must thicker new friction material, the gap where between the pads where the disc is located becomes too small, also, the pistons have only so much adjustment available - so to sort this out, when you renew the pads you need to wind in (and press) the pistons back to their initial "zero'd" setting.
 
Edit:- pistons are fitted onto a screw thread (as well as being hydraulically operated) so that is why you need to wind back and press back, pressing back only, if you managed it would mean damaging the callipers.
 
Another Edit:- as you seem to have a 2004 1.2 Fabia you will have drum brakes in the rear, so a G clamp is good enough for the front callipers.

If you are now getting reports of insufficient flow now, maybe have another look at where the EGR valve pipe enters the inlet manifold, you might just find that the port is gunged up and needs clearing.