Read the recent topic,my problem is slightly different.I have replaced the o-ring in the steam wand and and valve seat/o-rings in the valve assembly.Done this twice before (my silvia is 7yrs old) with no problems.
This time I cant seem to get a good seal on the steam wand,its leaking steam when frothing from the nut area......tightened,still same........disassembled and put another o ring in ,same result.

Is it possible the actual steam wand has worn at the end where it joins the valve assembly and cant seal properly? When I look at the end of the wand it has no collar or bevelling or flange etc just a straight forward cut pipe??

One other question the o ring for the steam wand goes on the end of the wand before insertion into the valve assembly,am I right in thinking this is then eased into the valve assembly coupling before tightening the lock nut? Im assuming so.