Hello everybody, I’m new here, and I might be looking for the solution to my problem this way. Screw around my 68 Ford Mustang Coupe for about half a year and I’m almost finished for the first Tüv performance. Unfortunately, I’m stuck with the following problem: I had a brake power amplifier with main brake cylinder ( one unit ) sent from the USA for retrofitting for this model (which had no amplifier before! ). So now I’ve got the old main brake I found that the pressure shot into the brake fluid tank, so I vented it with the lid. After the airing, I got the vacuum from a free, well-sucking connection to the carburetor. I thought everything was done and put myself in the car and started the engine. Now I have absolutely no brake pressure with the running engine!! If the engine is standing, my brake pressure is back! Fr age: Have I made a mistake when installing it? Can someone give me a good tip? I’m already playing with the idea of building everything back and driving it to Tüv without a brake booster. I’m grateful for any help! Greeting Dave