Yes, it is a mechanical guage with the tube and compression fitting. I think the compression fitting is okay. It "appears" that it is leaking from the threads that screw into the block, but I am not positive. My first move is to try the teflon tape route as it is the easiest. If it leaks after that I will replace the compression fitting. I'm hoping the tape will fix it as I don't want to try to find the correct size compression fitting. I remember it as being very small........