Faulty valve stem extensions cause flat tire

ok . Now I know about what you are talking about. When you buy them make sure it's Alligator brand, model V2b. There are many Chinese clones of this in the market. Clones go bad very often. Alligator branded cap is a bulletproof item.

 

I was always told the cap was to seal it. It does have rubber seal in it. That's why I thought metal caps were mandatory.
I always use this kind on inside tire and all you need is 3/8 socket 3/8 drive with 4" extension.
https://www.amazon.com/HALTEC-N-1202-Chrome-Plated-Valve/dp/B01FCATQDO

Caps that work as stems? Might as well run no caps.

 

If you want fool proof, run the PLAIN stems , metal caps, and I keep the tool to remove the cap on inside aluminum wheels is only like 2 bucks, so I keep one in every truck, my service truck and one in the shop.
The manufacturers claim a tire will naturally lose 2 pounds a month, I think some do and some don't.
The metal caps will somewhat seal, but if the core is leaking, it will bleed through, a lot of the time when a guy checks his tires some crud will get under the core, where it doesn't seal back right, and will be low the next morning if not careful. I always keep a close eye on them for a few days after I check them all.

There was no cheap knock offs for the extensions or the equalizers way back when they first came out, and that is when we started replacing tires because of them.

 

Caps seal better but trying to get drivers to check the pressure, let alone remembering to reinstall the cap, is probably near impossible. Some will drop a gauge on them with pressure caps.

The pressure caps are less prone to getting getting gunked up and leaking than a lone schraeder valve is. Plus it’s two seals as opposed to one. I think sealed caps are the best option.

My Pete has a TPMS which is very convenient.

 

I do not like the pressure caps at all, like I said the tool to remove and replace the caps is only a couple of bucks. Most drivers never check the pressure, and if it was my truck and it comes through the shop every so often, I would not want them too unless they suspect a low tire anyway.