Thanks for that crucial piece of info.

Just on dark, exasperated, cheap tools laying scattered about the street, mothers clutching their children staring aghast at struggling legs splaid and torrent of abuse emanating from beneath the front of the car - I heard the crack of movement from the adjustment nut.

I was just about to give up.

Following morning, pump was replaced.

Everything went back together and the car is mobile again.

cheers.