Review on Universal Black A/C Valve Core Remover/Installer by MASTERCOOL - Model 58490 by Doug Booth

The tool is good, but there is a small solvable problem. When removing large valve cores, e.g. B. the Ford high pressure valve, you may have trouble installing the core through the tool. The problem is the O-ring that seals the system port on the tool ball valve. As you tighten this adapter, the o-ring will shrink and bulge. This restricts passage through the tool and causes the core to fall out of the tool. I had to tighten this connection with my fingers and see if the core would fit. It worked, but it took a few tries to figure out why the kernel kept crashing.