Do tires lose air if the air tire valve cap is missing?

The only part of your vehicle that comes into contact with the road surface are the tires. If your tires are not properly inflated, you are in danger. That’s why you take the time to ensure proper inflation and good condition of your tires. So what happens if you lose your air tire valve cap? Do tires lose air if the air valve cap is missing?

When the tire valve cap disappears, air should not be lost. Air will not be able to escape from the tire just because a plug is missing. There are reasons to have the valve cap in place, but keeping air inside the tire is not a reason.

In this guide, we discuss the function of the tire valve cap. We also discuss how tight it should be and show the reasons why the tire will lose air. At the end of the article, you can read more about the different types of valve stem caps and the cost of replacement.

What is an air tire valve cap?

The valve cap is not used to prevent air from escaping from the tire. Whether the cap is on the stem or not should have no effect on whether the air remains intact. However, it has an important function that should not be overlooked.

When driving the vehicle in snow, water, mud, and dirt, the valve stem cap prevents the valve from becoming contaminated by debris and mud. For example, if too much mud got into the valve, it could be damaged. You may also have trouble inflating tires with mud buildup in the valve.

Are your tire valve caps falling off?

There are times when the tire valve cap may fall off. If you haven’t tightened it properly, it could fall off on its own. That’s why it’s important to secure the lid.

There is also the possibility that an impact could cause it to explode. If you scrape the car against the pavement, the scraping effect could also dislodge the stem cap. It can also damage the stem itself, which can cause an air leak.

However, the most common reason tire valve caps come off is that they are not installed correctly. When you remove the caps to fill the tire, it is easy to misplace it. When filling your tires, place the valve caps in a safe place to reinstall them.

Are tire valve caps universal?

For most models, the valve stem caps are universal. You can walk into any auto parts store and get replacement valve caps that fit your tires. In fact, it is difficult to find them sold individually.

However, if you drive specialized farm machinery or heavy trucks, the valve stem will likely be different. You may need to purchase valve caps from a tire store.

How much should you tighten valve caps?

When tightening the valve caps, you must turn them until they are hand-tight. Do not use tools on valve covers, as they should never be this tight. If you overtighten them, it could cause damage.

When replacing the valve cap, place it on the stem and turn it counterclockwise a half turn. This ensures that the cap is properly seated on the threads. Once it’s secure, you can tighten it until it won’t go any further, but don’t overtighten it.

Reasons why tires lose air

1. Broken valve stem

Although the valve cover will not cause air leaks, a faulty valve will. However, the level of air that escapes will depend solely on the severity of the damage.

It is possible to have a small, barely noticeable leak. On the other hand, it could also be leaking enough that you can hear the air coming out.

2. Tire puncture

If you hit something on the road, it can puncture the tire and let the air out. The most common items are screws, nails, and other debris left along the way.

Depending on how the puncture occurs, it may automatically plug the hole, so you won’t notice any air loss at first. Once air starts coming out, you may be able to put on a patch or plug. However, there are also cases where the puncture cannot be repaired and a tire will need to be changed.

RELATED: Are Tire plugs or Tire Patches Better?

3. Damaged wheel

The tire can be damaged if it hits something on the road. Hitting a curb, hitting a pothole, or hitting road obstacles can damage the wheel itself. If the tire does not sit properly on the rim, air could leak.

In most cases, damaged tires cannot be repaired. You would like to replace the tire to ensure good safety on the road.

RELATED: How much do tires cost?

4. Broken pearl

The bead of the tire is where the rubber seal and the wheel meet. If the cable is not properly sealed, air may escape.

This happens if the cable is damaged. It can also occur if debris gets between the wheel and tire, allowing air to leak.

5. Old tire

Tires age, especially if they are not used. When a tire rests, especially in the sun, it can become a victim of dry rot.

Even if it is used, over time it will begin to wear out. As the tire becomes brittle, the tread separates, causing an air leak.

RELATED: Dry Rot Tires: Warning Signs, Replacement, Prevention and Safety

6. Temperature changes

It’s always a good idea to check tire pressure when the temperature changes. This is because the outside temperature has a profound effect on the amount of air in the tire. Although the fluctuation does not cause air leaks, it changes the atmospheric pressure density.

When temperatures drop, tires begin to lose air pressure. The opposite is true, with temperatures and pressures increasing at the same time. If the temperature cools quickly, the tire may appear to have an air leak.

Over time, tires will naturally lose air. The air molecules will change in pressure and composition, causing the psi to drop. That’s why you want to check your tires monthly, at a minimum. With regular inspections, you can catch any problems before they affect your safety on the road.

Missing Tire Valve Cap Replacement Cost

You can purchase a large package of tire valve caps at your local auto parts store for $10 or less. If you need something for a heavy truck or are looking for something stylish, you may pay more than average. Plus, you don’t need anyone’s help to install the valve stem caps; it only takes a few minutes.

If you need to replace a tire valve stem, it’s also a fairly simple process. If you can do it yourself, it could cost you around $10. Otherwise, expect to spend between $25 and $50 at your local tire store.

Different types of valve stem caps

There are several types of valve stem caps you can choose from when you visit the auto parts store or tire store. Most people opt for cheap plastic plugs. These work very well under normal driving conditions and will not cause any unusual problems. You can buy a large pack of these caps to have on hand in case you lose one.

There are also metal dome lids. These are better in higher temperatures, such as when you’re racing or driving a high-performance car. There are also metal knurled caps that make tightening or loosening easier. You can also find some with a hex head design. With metal caps, you will see a special O-ring or other gasket that holds the valve securely.

However, we do not recommend using aluminum or metal tire valve caps instead of plastic, even though they look better than standard caps. The reason for this is that the aluminum and metal cap can begin to corrode and rust, which can make it impossible to remove them without damaging the air valve stem.