2001 Malibu
 

Someone help please. My 01 Malibu blew a brake line a few weeks back, come to today finished replacing rear drums, shoes, and hardware. Go to bleed brakes, can't bleed, was able to gravity bleed, car is not running I have pressure for days. Turn car on lose all said pressure back to the floor. No leaking of any sort from any where. Brand new brakes all the way around.

Did you bleed the master cylinder before bleeding the brakes?