I was driving home on the motorway today and, after about 20 mins of driving, I pressed the brakes but the pedal went almost all the way to the floor before there was any effect. It was very worrying to say the least! It stayed like that for about 5-6 miles before returning to normal for the last 10 miles or so of my journey. Has anyone else experienced this? What could be the cause? This has never happened before on this car or any previous car of mine.

any recent brake work carried out ?

No, nothing done to brakes at all in the last year

Sounds like a symptom of a faulty master cylinder.

I was driving home on the motorway today and, after about 20 mins of driving, I pressed the brakes but the pedal went almost all the way to the floor before there was any effect. It was very worrying to say the least! It stayed like that for about 5-6 miles before returning to normal for the last 10 miles or so of my journey. Has anyone else experienced this? What could be the cause? This has never happened before on this car or any previous car of mine.

Does the SDi go fast enough to need brakes??

Sounds like a symptom of a faulty master cylinder.

yes, i could be a vacuum/servo problem