Cooling system pressure tester adapters

[David T]

I have a professional one from NAPA. I have noticed that it leaks where it connects to the header tank. Looks like the system is leaking but it is just the tester itself. The plastic tank had a piece of metal embedded in the neck to keep it from deforming but over time it still deforms. Your tester and adapter is probably correct, it is the neck on the plastic tank that is the problem. In any case you should replace the plastic tank ASAP before it cracks or splits. Harbor Freight is not what it used to be. All they sell now is Chinese stuff and it is not of the highest quality (putting it politely).
David Teitelbaum