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What To Do If Your Bicycle Schrader Valve Is Leaking

A bike Schrader valve and core sitting on a white surface.

A bicycle Schrader valve allows you to inflate your bicycle tires. Schrader valves are pneumatic valves that are not limited to bicycles but can also be found on car tires. When you have a leak in your bicycle Schrader valve, you’ll know it, but what can you do to fix it?

If a bicycle’s Schrader valve is leaking, first remove the Shrader valve from the core stem using a Schrader valve core tool. Once removed, you can inspect the parts to see where the leak is. If the Schrader valve is damaged, it should be replaced.

Schrader valves were designed to last a long time, and usually, the most common reason why it may be leaking is due to dirt being stuck in the valve. Some bicycles are made with inferior parts, or the valve may not be secured correctly which can also lead to leaks in the Schrader valve.

Luckily there are easy ways to fix the leak and avoid having problems with the Schrader valve again.

What Causes A Bicycle Schrader Valve To Leak?

To understand how to fix a bicycle Schrader valve, you’ll need to know how it is structured. A Schrader valve has a stem with a built-in check valve. The check valve is kept closed by the use of a spring. When pressing down on the pin in the spring, the check valve opens, allowing the air to flow in or out of the valve.

The spring keeps the check valve closed and prevents it from losing air when the pin is released. This is why you need to press the pin down to ensure the air doesn’t leak when you put air in your bicycle tires.

The leading causes of a leak in the Schrader valve include:

  1. The Schrader core. The Schrader core is the component that is pressed down when inflating the tires. If the Schrader core is damaged, it can cause air to leak out of the Schrader valve. If there is a leak in the Schrader core, the best way to fix it is to replace the Schrader valve.
  2. The check valve. If the check valve has problems sealing or is damaged, it can cause air to leak out. If the check valve is causing the leak, it should be replaced.
  3. The O-ring. The O-ring is a rubber ring between the valve stem and the bicycle tire rim. It can leak if the O-ring is not secure, fitted correctly, or damaged. Therefore, when replacing the O-Ring, it’s also a good idea to replace the Schrader valve to avoid leaking in the future.

Besides damaged components of the Schrader valve, there are a few other common reasons why a bicycle Schrader valve leaks. These include:

  • A loose or ill-fitting valve will let air escape
  • Clogged valve stem– dirt or rust can clog the valve stem
  • The stem cap is broken or loose
  • An old Schrader valve that bends and is rusty
  • A faulty tire pump can cause the air to leak out of the valve and will not allow the tires to inflate correctly

How To Tell If Your Schrader Valve Is Leaking?

The best way to determine if a Schrader valve leaks is to inspect it. To do this, press down on the Schrader core valve and listen for any air escaping.

Another method to determine if there are any leaks is to use soapy water on the Schrader valve. If there are bubbles, you know there is a leak.

A bike pump on a bike tire with hands pumping it.
If the valve is leaking, a bike tire won’t inflate correctly

How To Fix A Leaking Bicycle Schrader Valve

To fix a leaking Schrader valve, there are a few tools that you’ll need. (They are all available on Amazon and I’ve linked to the specific product where applicable). These tools include:

In addition, there are a few steps to fix a leaking bicycle Schrader valve. These include:

  1. Remove the Schrader core from the valve. To find the leak in your Schrader valve, remove it from the core valve stem using your Schrader valve core tool.
  2. Check the O-ring and the valve. The valve and O-ring are common areas where leakages occur. Check the O-ring and valve to see if this is the cause of the leak.
  3. Replace the Schrader core with the new core. The new Schrader core should be inserted into the stem. Once fitted, put the check valve back in place.
  4. Pump up the tires. Once your valve has been repaired, pump up your tires and do a final check to ensure there are no more leaks.

Is A Schrader Valve Less Likely To Leak Than A Presta Valve?

Schrader and Presta valves are the two most common valves found on bike tires. Schrader valves are built more robust compared to Presta valves. However, both types of valves are susceptible to leaking.

Presta valves are tall and thin in design and are usually fitted on more expensive bikes.

Schrader valves are broader and shorter in design and are universal valves. Schrader valves are cheaper to maintain and only allow air in one direction, which lets you keep an eye on the tire pressure.

NOTE: While both types of tires are susceptible to leaking, there is no way to determine which valve is more likely to leak.

It’s best to take care of your bicycle, and regularly check the valves for leaks to avoid further damage to the bicycle.

FAQs About A Leaky Schrader Valve

If you’ve ever dealt with a leaky Schrader valve, you know there could be a few reasons it’s leaking. Besides this, the best way to avoid leaky Schrader valves is to take care of your bike and replace the valve as soon as you notice a leak.

If there is a small leak, it is possible to repair it with tire sealant. In other instances, if the leak cannot be repaired, the Schrader valve should be replaced.

How Can You Tighten A Bicycle Schrader Valve?

You’ll need a Schrader core valve tool to tighten a bicycle Schrader valve. You can also use a screwdriver, but this will be a bit more challenging than using a Schrader core valve tool.

What If I Can’t Find The Leak In The Schrader Valve?

If you aren’t able to find the leak in the Schrader valve, it is best to get it replaced. They are cheap to replace and a much easier option than searching for a leak that can’t be found.

How Much Is Ths Cost Of Fixing A Schrader Valve?

Replacing a bicycle Schrader valve is not expensive. You can either replace it yourself or take it to your local cycle shop to be replaced.

If you’re replacing it yourself, you’ll need a Schrader core valve tool and a new Schrader valve. These two parts should not cost more than around $8. However, if you are getting it repaired by a professional store, you can expect to pay around $20-$35.

Does The O-Ring Need To Be Replaced When Replacing The Schrader Valve?

The O-ring does not need to be replaced if it is not the cause of the leak. Generally, the leak occurs in the Schrader valve due to damage or wear and tear.

However, the O-ring can also leak. If it does, it’s best to replace it with the Schrader valve as a precautionary measure.

A brown bike tire with the valve pointed downward.
Replacing the Schrader valve is the best option


If your bicycle Schrader valve is leaking, it’s best to locate the source of the leak and try to repair it. If the leak can’t be repaired or you can’t find the leak, you can replace the Schrader valve.

In most cases, the valve is clogged or has dirt in it, which blocks air from pumping up the tires. Fixing and replacing a Schrader valve is the best option when there is a leak since it is:

  • quick
  • easy
  • cost-effective

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