How to Replace a Wheel Valve

I had a slow puncture and it wasn’t from my tyre?

I had just pumped my tyre up. When I disconnected the foot pump, I noticed that some air was escaping. I placed my finger over the end of the valve and could hear the noise change as I moved my finger (from the escaping air). On closer inspection, I found that the valve was leaking.

A 'Schrader' Type Wheel Valve
A ‘Schrader’ Type Wheel Valve
Note:

This article applies to most wheels (or things) that are filled under pressure via a valve stem and a Schrader type valve… I.e. Cars, vans, trucks, motorcycles, wheelbarrows, bicycles, bikes, refrigeration, air conditioning systems, etc, etc.


How do I Replace the Valve?

It’s easy to change a wheel valve core (with the aid of a valve tool). Sometimes it can be a bit stiff to undo, but this is usually when the valve cap has gone missing…

Topics:

Note:

Be careful with tyres… A tyre is a pressurised container. Any damage, or incorrect repair can cause a sudden loss of air which could be dangerous at speed (a blowout). Therefore please take care (any work you may carry out is at your own risk).


Testing for Leaks on a Wheel Valve...

What to look for?

We can test the valve and valve stem with some soapy water (as long as there is some air in the tyre).

  1. Use a brush to apply the soapy water. Just apply a small amount on the valve (the threaded part). As you can see from the image, a small leak will give you some bubbles.
Testing a Tyre Valve With Soapy Water
Testing a Tyre Valve With Soapy Water
  1. If you see bubbles coming from any other part of the valve stem (not the threaded part at the top), or you can hear air is escaping when you move the valve stem with your finger. You could have a perished, or damaged valve stem. I have another article on replacing this… ‘How to Replace a Wheel Valve Stem (link open in a new tab)…

Tools Required:

To remove a wheel valve, you need the following:

  • Valve core removal tool.
  • A screwdriver (or similar to release the air).
Notes:

If you’re lucky, you can sometimes remove a valve core with long nose pliers, a small screwdriver, or make your own tool. However, the tool is inexpensive and you’re more likely to have success with the correct tool for the job…

Replacing a valve is straightforward and only requires an inexpensive wheel valve removal tool. There are a few different looking valve tools available. Usually, the only difference between them is the number of added features.

A 'Schrader' Type Valve Core Removal Tool (with Multiple Features)
A ‘Schrader’ Type Valve Core Removal Tool (with Multiple Features)

If you’re lucky, you may already have a wheel valve core removal tool. Sometimes you can find the tool included with air pumps and tyre pressure gauges. The image below shows a wheel valve removal tool on the end of a tyre pressure gauge.

A Wheel Valve Removal Tool on the end of a Pressure Gauge
A Wheel Valve Removal Tool on the end of a Pressure Gauge

The steel tools are usually a lot more robust than the plastic items. In the image below, the plastic tool is starting to get a bit chewed up…

A Wheel Valve Removal Tool on the end of a Tyre Pressure Gauge
A Wheel Valve Removal Tool on the end of a Tyre Pressure Gauge

Video:

‘How to Replace a Wheel Valve


How to Replace the Wheel Valve:

As long as you have the tyre valve tool, it’s an easy task to replace the valve.

What Are You Trying to do?

The inside of the valve stem has a thread which the valve screws into. To remove the valve core, you have to unscrew the valve. The center of the valve (the round bit in the middle) passes through a hole in the valve tool, allowing the tool to grip the two flat edges (see the image below), and undo the valve.

The image shows an 8mm Schrader type valve fitted to a bicycle inner tube.

Undoing a 'Schrader' Type Valve (8mm) - This One is Fitted to a Bicycle Inner Tube
Undoing a ‘Schrader’ Type Valve (8mm) – This One is Fitted to a Bicycle Inner Tube

Replacing the Wheel Valve:

Initial Check:
  • Before removing, check if the valve is tight (and that it’s not just a loose valve).
  • If it is loose… Tighten and re-test for leaks with soapy water.
Removing the valve:

– For Safety

Let any remaining air out of the tyre. So the valve core doesn’t shoot out under pressure (when undone)…

  1. Press on the valve with a screwdriver, or something similar…
Replacing a Tyre Valve - Letting Air Out of the Tyre
Replacing a Tyre Valve – Letting Air Out of the Tyre
  1. Place the wheel valve removal tool on top of the valve. Insert the tool onto the flats of the valve (so the tool grips the valve) and unscrew.
Replacing a Tyre Valve
Replacing a Tyre Valve
  1. There may still be some trapped air that escapes whilst you unscrew the valve.
Replacing a Tyre Valve - Undoing the Valve
Replacing a Tyre Valve – Undoing the Valve
  1. Remove the valve, (if needed, long nose pliers may help in retrieving the valve from the hole).
  2. Insert a new valve and tighten.

If defective, do not try and repair the existing valve! Failure (a sudden loss of air) could be dangerous at speed (a blowout). Always replace with a new valve.

  1. Re-inflate the tyre to the recommended pressure and retest (if necessary).
  2. Always replace the valve cap. This keeps dirt and moisture out, and protects the valve.
A 'Schrader' Type Valve (8mm)
A ‘Schrader’ Type Valve (8mm)

The Different Types of Wheel Valve:

There is usually only one type of valve fitted to an air filled wheel. A Schrader valve. Whereas with bicycles, there are two types, Schrader and Presta (Presta is smaller, for narrow bicycle wheel rims).

The Different Types of Wheel Valve & Where They are Fitted:
Wheel Valve Types
Name Fitted Size
Schrader Cars 8mm
Bikes
Trucks
Motorcycles
Bicycles
Presta Bicycles 6mm

‘Snap-In’ Wheel Valve Stems:

The length of the valve stem is specified using the following references (see the table below):

‘Snap In’ Valve Stems – The Different Lengths:
Wheel Valve Stems
Tire & Rim No. Length
TR412 22mm 0.88″
TR413 32mm 1.25″
TR414 38mm 1.5″
TR415 44.5mm 1.75″
TR418 51mm 2.00″
The most common ‘snap-in’ valve used for passenger vehicles is the TR414. Max inflation pressure 65 psi.

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