I don’t think valve stem caps keep air in. I think they simply stop dirt from getting into the valve stem which could cause it to become non functional or the valve to stick open on the tire to deflate
The ones with the rubber seals keep air in. A lot of new cars have those and a lot of cars with tire pressure sensors require them. Regular covers without the seal don’t keep air in obviously but I still wouldn’t trust the ones 3d printed by a random person because I don’t know what their QC is. The ones that go over original covers are the best either way.
The only thing the cap does is prevent things from damaging the core.
The core is a small piece of metal, spring, and rubber seal. This does all of the work holding air in.
The stem is the housing for the core.
The cap is just protection.
Do an experiment for me. Remove the core and put the cap back on. It will not hold air. Some threads and a piece of plastic that constantly gets removed will not hold air pressure.
Yes, you should have a cap. The cap prevents damage.
I see where you’re coming from but
“Metal, and some higher quality hard-plastic valve stem caps, often have a rubber washer or seal inside to help make an airtight seal. This type of cap protects from dirt and moisture and also helps prevent air from escaping from a slightly leaking Schrader valve.” (https://www.bluestar.com/get_informed/article/tire-valve-stem-caps-do-your-tires-need-them)
“helps prevent air from escaping from a slightly leaking Schrader valve.”
“Helps” is doing a lot of work for you there. You have a damaged valve and it would need replaced.
It also doesn’t help because the damage to the valve that would come from the moisture from the INSIDE of the tire.
If you’re that worried just buy a 100 pack of valves cores for $5 and just swap them every time you change your tires. You’re vehicle will explode before you run out of cores, and then you don’t need to worry about replacing the $15 fancy caps ever.
I don’t think valve stem caps keep air in. I think they simply stop dirt from getting into the valve stem which could cause it to become non functional or the valve to stick open on the tire to deflate
The ones with the rubber seals keep air in. A lot of new cars have those and a lot of cars with tire pressure sensors require them. Regular covers without the seal don’t keep air in obviously but I still wouldn’t trust the ones 3d printed by a random person because I don’t know what their QC is. The ones that go over original covers are the best either way.
I’m a mechanic.
The only thing the cap does is prevent things from damaging the core.
The core is a small piece of metal, spring, and rubber seal. This does all of the work holding air in.
The stem is the housing for the core.
The cap is just protection.
Do an experiment for me. Remove the core and put the cap back on. It will not hold air. Some threads and a piece of plastic that constantly gets removed will not hold air pressure.
Yes, you should have a cap. The cap prevents damage.
I see where you’re coming from but “Metal, and some higher quality hard-plastic valve stem caps, often have a rubber washer or seal inside to help make an airtight seal. This type of cap protects from dirt and moisture and also helps prevent air from escaping from a slightly leaking Schrader valve.” (https://www.bluestar.com/get_informed/article/tire-valve-stem-caps-do-your-tires-need-them)
“helps prevent air from escaping from a slightly leaking Schrader valve.”
“Helps” is doing a lot of work for you there. You have a damaged valve and it would need replaced.
It also doesn’t help because the damage to the valve that would come from the moisture from the INSIDE of the tire.
If you’re that worried just buy a 100 pack of valves cores for $5 and just swap them every time you change your tires. You’re vehicle will explode before you run out of cores, and then you don’t need to worry about replacing the $15 fancy caps ever.