Hmmm - seem to have a leaky connection

Off to the air compressor shop tomorrow - get s pare and then see if just changing a couple of the o-rings will do the trick. Of course my box of 36 different sized metric o-rings doesn't have any in the right size but that's just par for the course...

 

I guess this connector has been flowing compressed air for a good five years of light use now.....

Done