Can anyone help with identifying this connection it appears to be plastic on the end of a steel pipe below the inlet manifold. It is held in place with a couple of plastic wedges. I am trying to replace it as it is cracked but I am having problems getting it off the end of the steel pipe. I have released the wedges and was expecting it to drop off and reveal an 0 ring or something but it is hold on firmly. Is the likely to be just corrosion holding it or am I missing something?