Schrader Valve Explained

What is a Schrader Valve, How Does It Work and What Is Its Function?

Automotive design has come a long way since the Ford Model T. However, and some things haven’t changed much. If your vehicle has tires or an A/C system, the chances are that you’ll find a Schrader valve in your car. This tiny component can often be the difference between coming home or staying stranded somewhere on the road. Knowing how it works could come in handy someday. Our goal today is to scratch the surface on Schrader valves and discuss why they’re the perfect choice for highly pressurized systems.

History of the Schrader Valve

The origin of Schrader valves can be traced back to 1894. The reason these valves exist today is the ingenuity of one man – August Schrader. August was a true inventor whose passion for innovation never went away. Schrader had a business that was mainly dealing with rubber products. Some of his earlier customers were the Goodyear brothers for whom he designed all kinds of fittings and valves.

However, it wasn’t until 1890 that August heard about cyclists in England using pneumatic tires. Despite being 82 years old at this point, he quickly recognized the need for a valve that would make using such pneumatics easy. By 1894, Schrader had created his legendary valve, patented the valve and the cap, and introduced the technology into the automotive world.

Not much has changed since then. Modern valves of this type are improved, but the core principles remain.

What is a Schrader Valve, How Does It Work and What Is Its Function?

What is a Schrader Valve?

If you drive a car or ride a bike, there’s a good chance that you’ve already dealt with a Schrader valve at some point in your life. These valves, also called the “American valve” can be found on tires all over the world. So what exactly is a Schrader valve?

Schrader valve consists of two main components – the threaded hollow shell and a poppet valve that sits inside. The valve is designed in such a way that it allows the user to either add or remove air or refrigerant in a high-pressure environment without any leakage.

A/C Schrader Valve
Shop Now

What are Schrader Valves Used for?

The most common use for this type of valve is in pneumatics. Almost every tire in the world will come with one of these valves. However, it is also worth mentioning that a Schrader valve is used in air conditioning systems. As a matter of fact, it’s a perfect tool for A/C applications. The ability to bleed the system or add more gas without any loss of pressure makes working with A/C systems much easier.

Performing maintenance on high-pressure systems without having to take them offline or depressurize them is a powerful tool in the A/C business. This type of valve also makes fixing small mistakes very easy. For example, if you were to overfill the A/C system accidentally, you can quickly release the excess gas. The same goes for tires.

A/C Schrader Valve
Shop Now

Automotive Air-Conditioning

If you pop the hood on your car and look at the high pressure or the low-pressure A/C line, there’s a good chance that you’ll find a Schrader valve sitting on each of these. Although different than the ones you’d find on tires, the valves located in A/C systems perform the same task.

Since they’re used continuously during A/C maintenance, Schrader valves are one of the main culprits behind leaky A/C systems and other complications. Fortunately, replacing them is often fairly easy and requires nothing more than a specialized tool.

However, keep in mind that replacing the valve requires you to dispose of the refrigerant as mandated by your local regulations. Once the system is dry, the replacement process comes down to unscrewing the core from the valve using the specialized tool and replacing it with a new one.

If you’re looking for Schrader core for your A/C system, head over to our store and input your vehicle’s info. We carry a wide range of replacement cores for European cars as well as caps.

A/C Line - Compressor to Condenser
Shop Now


Schrader valve maintenance is fairly straight forward. Although the valve itself is important, the cap that screws on top of it is every bit as essential. In fact, you could argue that the Schrader valve cap is vital for the proper operation of the valve.

One of the best ways to keep your tires always inflated and your A/C working properly is to have the caps properly mounted and accounted for. An exposed Schrader core is suspect to environmental effects and debris, which will substantially shorten its lifespan.

If you have a faulty core on one of your tires and want to replace it, make sure that let all of the air out of the tire first. Better yet, take the wheel off the vehicle and bleed the air out completely. Trying to replace a faulty core on a pressured tire can lead injury if you’re not careful enough.

A/C Hose Assembly - Compressor to Evaporator Pipe
Shop Now

The Cap

We’ve already mentioned that keeping the cap tightly screwed on the valve is one of the best ways to prevent any problems. It just so happens caps are lost all the time. Let’s be honest, most of us are distracted by one thing or another. It is so easy to forget the cap when you’re checking the pressure in your tires. It happens to everyone.

Here at, we know this all too well. We also carry one of the most extensive catalogs of parts for European vehicles. Our current offer covers everything from core engine components to, you’ve guessed it, Schrader valve caps.

Schrader Valve Cap
Shop Now

If you own a European car and are looking to replace your missing caps, simply go over to our store, input your vehicle’s make model and year into our system, and you’ll find the right caps.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.