Hi Ian, yes my mate tried to increase the pressure but it has not got it to kick in right. I am reluctant to try doing that further due to fear of making hard work for the compressor as m_c mentions. I think perhaps it would be a good idea to go the part you gave a link for. Sorry the pictures were not great I see what you mean when I looked at them again! Many thanks for your help and the link and I think I may go down that road. Suesi