Brake Problem

What is your question?

I did the brake recall last year, I put 3 master cylinders on, I have replaced the calipers twice and I still get air in the system and the brakes go out. I have had several close calls on having wrecks. I have had it at Cadillac several times. They keep it for days on end and can not fix it. Does anyone have any ideas? I cannot get Cadillac to do anything to help.