First, he has removed the electric sender and is using a tube to a mechanical gauge.
Second, the tube should use a compression fitting. The threads don't seal it. If it is leaking, it is not because of the threads. (unless it is leaking between the adapter and block, then it is the threads)
Second, the tube should use a compression fitting. The threads don't seal it. If it is leaking, it is not because of the threads. (unless it is leaking between the adapter and block, then it is the threads)