Pulling my hair out here, I have an 87 TII. I have swaped a new engine into this car. When I first got this car it had been sitting for a year or so. When I got it home I noticed the brake pedal went almost to the floor but didn't look into it further figuring the brakes just needed to be bled. Bleed the brakes, pedal still went almost to the floor with little resistance. I had another master cylinder that I knew was good so I installed it, re-bled the brakes and the pedal pressure felt great. That is until I start the engine, then the pedal went almost to the floor again. I turned the engine off and the pedal pressure firms up. Next I pulled the vacuum line to the brake booster off, now the pedal pressure is firm when the car is on or off!? Is the brake booster bad/leaking? I have one that I can install but wanted to get some feedback before I went and removed the old one. Also I know that I have the connection correct from engine to the solid metal vacuum line to the brake booster. Help me Rotary Wan Kenobe you're my only hope.