Passat brakes

Good afternoon and thanks for the help.
I have a Passat of the year 95, a few days ago I tried to change the rear brake shoes but it was impossible for not being able to press the brake bombin and thus place the new ones.
But the problem is that I have now filled the brake circuit and I have been air inside, I have purged the 4 wheels but the brake pedal is still sinking, which makes me think that there is some other pirchar in the circuit to extract the air.
My question is any more potholes to purge the brakes? Or do I simply purged the wheels?
Thank you so much.

Look if the circuit was completely discharged and the entire brake fluid was emptied, for an oversight, it does not happen, you will have to bleed the pump, as long as you are left without liquid, if your vehicle has ABS or a multiplier of force, you will have to bleed this too, this is a small box where 4 can be Way of bleeding is from the most served wheel to the farthest, so the air is not returned. But there is a small problem if you exercised defiance on the pedel at the time of bleeding, it can happen that you decompose the pump, you have to step firm but soft a lot another, one hose to the brake to bleed and the other to the deposit and holy remedy, does everything easy

Thank you very much Karma, I will try what you say.