Thanks for the response but, it's the left hand outlet that has the one way valve and connects to the breather filter, and no the baileys shouldnt create an air leak because it replaces and plumbs into where the original breather system was, thats why i can understand why I had a leak!
Brand new hoses and jubilee clips, all 4 hoses where connected, 2 to rocker cover, 1 to sump, one to metering head, where could the leak be????