as Frenchy has already mentioned it probably needs tightening down a little, take the macro hose out and put an allen key down the inside of the fitting (3/32 i think, its one of the sizes in the standard tool kit with the gun) and tighten it up, if that doesnt sort it then it may be one of the orings in the fitting, the small one on the threaded part can be replaced with a #006 and the internal one is a 010 which if you dont have you can get from any Eclipse tech center or probably anywhere who services any kind of marker.
there is no mechanical part inside the fitting that can get damaged, it is made of 2 parts, the main body of the fitting and the steel collar which locks the macro line in place, both are very hard to damage and unlikely to cause a problem.
if you cant get it sorted please contact your local Eclipse tech center or Gerry at PE on
gerry.b@planeteclipse.com and he will sort you out