I recently bought a 34,000 mile 1.4 205XR. (Not a GTI ). I took the engine out to tidy up the sub frame and engine bay. I also fitted copper brake pipes all round and painted the servo and master cylinder. On replacing the engine and going to drive the car I now find when I press the brake pedal there is a hissing noise, and the engine cuts out. I have checked the vacuum pipe from the servo to the cyl. head and that seems fine. Is the servo the problem?
Thank you for all who answered. It turns out it was the servo. I replaced it with a second-hand one off e**y, made easy as I'd replaced the brake pipes with copper ones, and they bent out the way no problem. Going like a dream now.