Ive already tried blowing through the line and Its good. As for the rubber brake lines ,my only reason for not replacing those before the brake booster is because there is someone with a similar problem and hes already replaced everything that I have plus SS lines. The only thing that he hasnt tried replacing to fix it is the brake booster, thats why Im going to give it a shot. Ill find a link to his thread.

FSM= Factory Service Manual? I still dont have one, just a haynes. I should probably look into getting one...