How to Replace a Car's Tire Valve Core

One of the most common problems with a tire is a leaking tire valve stem. It causes a very slow leak, but eventually the leaking tire valve stem needs to be replaced. It’s not a large job and one you can easily do at home with a minimum of equipment. However, be aware that the leaking tire valve stem is at fault first.

Step 1 - Checking the Leak

The first thing to do is to establish whether the leak in your tire is from the valve stem or a slow leak in the tire itself. To do this, remove the cover from the valve stem and set aside, being careful not to lose it. Take some soapy water and spread it over the valve stem. Keep watching it. If it bubbles then you have a leak in the valve stem. If it doesn’t, the problem is in the tire so you should take it to a garage and have it repaired.

Step 2 - Removing the Stem

The tire valve stem can be removed and replaced. To begin you need to let all the air out of the tire. Press down on the valve and you’ll hear the air escaping. Keep the valve depressed until all the air has gone. Insert the valve core replacement tool into the tire valve stem. There will be a slotted end that fits around the stem. When it’s properly seated, turn the tool in a counter clockwise direction. Keep going until you’ve unscrewed the core and pull it out.

Step 3 - New Stem

Now you’re ready to insert the new core. Be aware that the stems are a one size fits all part. Put the new core in the valve and seat in centrally. Put the valve core tool over it and begin to screw it in, turning clockwise until it’s tight in the valve. Be careful not to overtighten. Once it’s tight and seated fully, remove the valve core tool.

Step 4 - Finishing

With the tire valve core replaced you still need to re-inflate the tire. You can use a foot pump for this or one that plugs unto the cigarette lighter in your car. The latter is the much easier option; all you need to do it attach the unit to the tire, plug it into the cigarette lighter and switch on the pump.

Using a foot pedal takes a great deal longer and requires much more effort. Be prepared to spend at least 15 minutes pumping as you inflate the tire, and change legs several times to avoid becoming too tired. Once the tire looks as if it’s fully inflated, check the psi with a tire pressure gauge. The owner’s manual for your vehicle will give the correct pressure for both front and rear tires.