After a lot of messing about unscrewing the cap, I realised it would have been easier to turn the machine on its side. Then from underneath you can remove the pipe, using a pair of pliers squeezing the circlip. You can then shake the pipe to remove any debri, & poke inside with ease to remove any foreign matter in that part. But the desription above helped me, as I wouldn't have known without reading the above first.
Paul Williams, Cheshunt, May 2010