Thank you Barnie,
I did not look at your answer before as the leaking stopped by itself.There used to be a patch of about 10" diameter puddle,so it is a mystery.Fortunately Potterton couldn't make one for me.
Peter
Peter, June 2007
unlikely to get new section , could try makers (potterton )for old stock,but first check mudhole covers and manifold gaskets which are prone to shrinkage and often only need tightening.