Review on Lichamp Automotive R1234YF Installer Standard by David Shah

I had the same problem as the reviewer who posted the video. The tool's ability to "hold" a loose valve core tightly depends largely on the small "ball" at the end of the valve core. It should "snap" into a small hole in the tool. Not all valve cores are the same. I was able to solve this problem by applying some lubricant to the end of the tool. And it seems to be holding up much better. Just remember to move slowly so the bar sticks to the end of the tool as you remove and insert. I used: Refrigeration Technologies RT201B Nylog Gasket/Thread Sealant. It is safe to use and will not damage the air conditioner.