I bought a new wika gauge for my fx streamline. It has a really slow leak. I put the end of the air tube in water and it is coming out of the hole in the side of the brass ring on the gauge that you put the wrench on to tighten it. No bubbles from around where the gauge goes into the air tube itself. I tried tightening a bit to no avail. I’m thinking this indicates the gauge itself is bad ??