Due to frequent checking of tire pressure with inflators with gage I've occasionally unknowingly loosened the valve stem core, later retightening / resealing the valve stem core with tool (pictured) when realizing a slow leak had developed.
If you have aluminum valve stems, you could do some real damage to the valve stem by over tightening the valve core. That tool is designed for really repairing or removing a broken valve core from the valve and to straighten the threads inside the stem and outer threads of the stem. If your car has rubber valve stems, they can take a little rougher treatment because they have brass threads. All you need is to snug the valve core to it seats. They have a special valve core torque tool also. If you have to replace the valve cores, make sure you buy nickel ones instead of metal ones. Here are my cheap recommendations below that I use for general purposes. The tool that you have is fine, but it would be easier to get in trouble with. Not trying to be a know-it-all, but tires have been my business for over 45 years.
Thanks for the direction. As one who has a tendency to over tighten things I was careful just to snug it closed. Curious to know if you've seen new cores fail, slow leak out of the box? On a related note I've never had a do it myself tire plug fail but I've had a couple suspected slow bead leaks continue that I didn't go far enough with.
Yes I have seen new defective valve cores like anything else things sometimes are not perfect. I assume you have aluminum valve stems? if so I have seen the stem its self leak. you can buy a valve stem seal kit at your local auto store that's not uncommon , the part number is 7020K made by Dill it is a service pack of (1) and oxidation as far as corrosion on the beads also like you mentioned too.
