How to Replace a Car's Tire Valve Stem
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 soap 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 plugged.
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 stem and you’ll hear the air escaping. Keep the stem depressed until all the air has gone. Insert the valve stem 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 stem and pull it out.
Step 3 - New Stem
Now you’re ready to insert the new stem. Be aware that the stems are a one size fits all part. You’ll need to purchase a stem that’s correct for your car so when buying have your tire size handy. Put the new stem in the valve and seat in centrally. Put the valve stem 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 stem tool.
Step 4 - Finishing
With the tire valve stem 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 engine.
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 fire, 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 from and rear tires.