Seal looks perfect, but it appears that it was the problem. I know this isn't best looking solution but it works like a charm. It took the Renault "specialists" 4 years and no results to find the cause, and only one afternoon for my friend and me.
ABS turns on @ 150km/h and I had 70-80% of pressure on the brake pedal.
My dad had the same issue on his Audi A4. Numerous times he complained of the brakes being unassisted at times when you really needed them. Took it in many a times and because it wasnt flaging up on the pc they let it slide.
At the time the letter was being drafted saying that its all ok just incase he was to have a crash due to them, the oldest technician took a look and found a slit in the vacuum hose...problem solved.
Yesterday I've found out that my AC compressor had gone - again. Had it repaired twice in the last 3-4 years. So I just bought a new one this time.
Also, ordered 12 W5W 1W SMD LEDs for the interior (2 LEDs have died in the past 4years, so I've ordered 12) week ago from Hong-Kong and they are already here: