SX pressure reg on vaccum side leaking air when doing a vac test
 

Hi all,

I've just checked my manifold pipework to check for leaks as idle still varies a bit although the new ecu update can control it now. It seems the SX fuel pressure reg has a leak when the engine is off, only slight, but when you put a vac tester on the line it drops slowly whereas the other pipes dont. Change the testing pipework and does the same thing so it's definately the regulator.
Anyone had to seal one before, does it need a top gasket on the screw and nut?