Brake issues after rotor and pads changed... Help!

Hello!

I have a A4 Avant 1.9 TDI (B6) and I have changed the front and rear rotors and pads last week putting brand new Ferodo pads and Brembo Max rotors.

After the pads "bedding process", the car seems to brake worst than before and sometimes (specially if I brake harder) the peddal goes hard and doesn't brake at all (almost nothing)... I even tryied to brake harder but it doesn't even activate the ABS... I can only feel this if I brake hard because during a normal driving it works fine...

What can be happening??
I have not dissambled the brake fluid lines and I have pushed the pistons with a standard C-clamp.
The front ones were easy, but on the rear ones I had to use a universal pair of pliers to scew the piston in at the same time as I was pushing the piston with the clamp.
Did I made something wrong during the equipment change? The only thing I didn't remember to do was to check the fluid level after pushong the pistons...
Should I bleed the system?? Is that an easy task to do?
Thanks
Regards