Further to the bleeding brake system - have flushed through 3litres of Dot4 to clear the silicone fluid out - bled the brakes -soft pedal - bled again with same result. Ignition on same result- soft pedal. Loosened the inlet pipes from the master cylinder to the ABS - one at a time - and bled 250mls out then re-bled whole system pedal pressure now okay.
The moral to this saga is pinch off each flexible to change the brake pipes ONE at a time and not let system drain dry. As a point of interest took the car to the main ALFA agent in Caen (Normandy, France) for a brake efficiency
test but they refused to touch the car as the brake pipes were NOT standard Alfa parts. Beware - the French look after themselves and will not fit any parts that they do not supply even if bought from another Alfa agent!!!
Thanks for all the advice found it very helpful.