Did something stupid

Not immediately, but it would be prudent to replace the cap, if only to prevent damage to the valve mechanism.

It’s always a good idea to think about the potential for foreign object damage, but in this case, it strikes me as unlikely that the plastic tire valve cap (Toyota part number 90942-05039, if you want a genuine replacement) would be able to do much to the alloy wheel, brake disc and caliper, etc., which we can safely assume were designed to handle occasional impacts from small rocks, stones, and other debris.

You could remove the wheel and inspect, but that operation isn’t without risk, and I’d be surprised if you find anything. The cap probably went into the wheel and then fell out when the car was driven away.

 

Time for some visual upgrades

 

The cap is there to keep the schrader valve inside the valve stem clean. You can purchase a set of caps at any auto parts store. My caps are green which signifies that the tires have been filled with nitrogen rather than air. Any cap will do but you may want to color match with your other caps.

Your cap probably went the same place that a 10mm socket goes every time I work on a car.

 

I was wondering where those keep coming from.

 

I had the same thing happen to me on my Gen III, but was able to fish it out of the wheel.

 

YES.
That cap really is just a dust cover......and replacements can be had cheaply at any auto parts store or places like WalMart.
Or a local auto or tire shop might give you one free.

Note: While it might seem reasonable for something like that to only go a few inches from where it is dropped, the actual distance often is a few FEET or more.

 

Or they're probably just laying around on the ground.

 

I'm all for worrying obsessively.
But my speculation is, that if the valve cover was dropped in the tire, then the vehicle driven, it's likely the the valve cover will never be found.
You could go out with a flashlight, and take a real close look, but it's likely it fell out somewhere between where the OP filled the tire, and home.
Myself? I'd probably take another look. But I think chances of finding it at this point, very, very slim.

Total Wheel Inspection would be the only definitive way to determine it's NOT there.

 

They are cheap plastic dust covers to protect the valve stem- as others have already said. There are exceptions but most are these.

If you wonder about the actual price you can get 100 of them for $1.39

100 pack Plastic Tire Valve Cap

 

My question is what should I do now?

Now would be a good time to meditate on the question of why they only come in black, and if it would be a good idea, or maybe a little bit obsessive, to paint them fluorescent orange.


Is it enough if I just find a replacement cap and put it.

Yep. Unless you like painting.

 

The cap doesn't hold the air in. If you lose air, it is because lack of a cap allows dirt or grit to get into the valve and prevent it from fully seating and sealing. But this won't likely happen until the next time you add air or check pressure, disturbing any grit that fell into the stem.

Personally, I wouldn't even bother to spend more than a few moments to search for or fish it out. It shouldn't be a problem (especially the basic black plastic ones) before it soon rattles out and is gone for good. I'd just grab another from the bag of spare parts kept for the many bicycle events I support. Parts scavenged from the dead tubes of riders being assisted, to hand out to other riders as needed.

About the only reason for others to spend more time fishing it out, is because they lack spares and fishing is quicker than shopping for a replacement.

 

Lol... How much do those cost?

 

$1 plus $1 shipping from

Wish

 

Stick with plastic replacement cap(s). Metal ones have been known to corrode and glue on, sometimes necessitating VERY expensive repair, including replacement of TPMS sensor.

A tip: when going in for new tires, take the valve caps of your current wheels, save them being chucked. You can save them for spares, or if you're not liking the new valve caps (Costco greenies for example), you can swap them back.

 

Wish, the only store where you need to actually Wish you bought somewhere else after you receive a torn beanie baby instead of the MSI Motherboard and cpu combo you actually ordered.


That said as often as I loose them I should have a hundred pack, same thing with tire pressure gages, I might splurge on the heavier cap with o-ring to reduce the very small chance of the Schroeder valve leaking to zero.

 

I go by the tire store, look around their water tank (where they check leaks) and grab discarded valve caps off the ground. Amazing. Actually, I am sure they would just give me one if I asked.

 

lol, yeah only ordered from them a few times, surprisingly have not been disappointed tho.
However, I only ordered very cheap items to date, and expect everything to be that way.

 

Have to admit, the writing in this thread reminds me of Shakespeare

"Much Ado about Nothing."

But, I will play along and confess to a dark period in my life and a crime that goes yet unsolved.

*********
I don't think I have ever paid for replacement caps. Used to save the caps that were on old bicycle tires that I was throwing away. I think I still have a bin in my shop with at least a dozen.

And, not too proud to admit this, but I think I can't be prosecuted for this theft anymore, since it happened in the early 1980s....

I was a young single guy and at work there was a woman a year or two older than I whom made it her mission to flirt with me -- she would walk up behind me and run her nails up and down my back.. She would say she got a new bra and then would lean over and let me see down her blouse. The thing is she was just a tease and never would go out with me or really see me outside of work -- and the funny thing is I was the only one she seemed to like to tease. BUT< she had an old pickup and it was known I was handy with tools, so I was roped into fixing said truck a couple of times.

Oh, I don't know, after a few months of this, one of the middle managers (a woman), called me in and said something to the effect of "You know that Lynndee is just taking you for a fool and taking advantage of you. It's been amusing to me, but I suppose I had better stop it because it is not appropriate. I could talk to her, but I think it will be easier if you just ignore her. A few rejections and she will stop. You are not the first one she has toyed with and probably not the last."

Well, I did not need to be hit over the head. And, honestly, Lynndee was nowhere near a raving beauty....so, I followed the advice and she quickly stopped her silliness. Of course, nowadays it probably would have been a whole Human Resources issue....

ANYWAY I remember working on my car one weekend and noticed one of my tire valve caps was missing. Hmm, wait....I have an idea. On Monday, I wandered around the office parking lot, bent down next to Lynndee's truck, removed one of her caps and I was good to go.

Again, not one of my proudest moments, but I got a certain glow of satisfaction every time I looked at that tire and saw her mismatching cap on my tire valve -- and I suppose some could say there was a bit of Freudian symbolism going on with that particular picture.