Letting air out of tires to maintain a recommended tire air pressure may be considered the easiest car-related D.I.Y. task by far for a safer, more comfortable driving experience. Driving with over-inflated tires can be tiring as they become stiff and brittle, causing a lot of vibrations.
The simplest method you can try to let the air out of tires is by pressing the thin metal pin found inside the valve stem with any thin, blunt tool like a long-nose plier or screwdriver. Be careful though, as you may accidentally puncture your tires, or damage your wheels, you may need also to take extra steps such as measuring the tire’s air pressure before and after you let the air out.
Why You Might Need to Let Air Out of Your Tires
The most common reason why there is a prompt need to let the air out of tires is because of over-inflation brought by different situations like you accidentally put too much air pressure, or the belief that a rock hard tire improves gas mileage. Additionally, certain events also influence a change in air pressure, like in a warmer season where air takes up more volume.
Heat-induced over-inflated tire
Heat causes molecules to bump into each other, the result is a more expanded surface area, This phenomenon is prevalent during warmer seasons, and your tire is not spared from this occurrence. Moreover, friction from both the rubber and the road, especially at high speeds could heat up the molecules inside.
“Over-inflated tire improves fuel economy” myth
This belief has been busted with numerous experiments, you can see it for yourself online through videos or detailed articles like the one here. The point is, compromised handling, control, and unnecessary tire wear outweigh the small gains from running with over-inflated tires.
The standard procedure whether you’ll change your tires or wheels for upgrade or replacement needs them to be fully deflated to work on them properly.
The vehicle is stuck on the mud or sand
Aired-down tires increase the surface area, and because they have a wider footprint, they won’t sink in as deep and could help you get out fast from being stuck. The recommended level is you let out at least 15 psi of air, and you’ll get out in no time if you’re lucky.
How to let the air out of tires to fully deflate them
To let the air out entirely of your tires is as easy as extracting the metal pin in the stem valve. However, you need to lift your car to do so to prevent damage brought by weight redistribution due to deflated tires.
- Lift jack and jack stand
- Needle-nose pliers
Lift your car
Deflating your tires completely when they are not suspended in the air can cause irreparable damage to the tire itself and to other mechanical parts such as wheels and discs.
To lift your car, first, locate its jack points, these are the strongest points in your vehicle’s under chassis, located on each side of your vehicle, behind the front tires, and in front of rear tires. Place the jack below these points and raise the car until you can slide the jack stands to all the corners. Then, you can slowly release the jack, removing them completely so the car is placed securely and independently by the stands.
Find the valve stem
The valve stem holds the metal pin that needs to be unscrewed to let the air out completely. This stem is usually located between the spokes sticking out the inner rim of wheels.
Remove the cap covering the valve stem
This cap made of plastic, rubber, or metal, prevents dirt and dust from getting inside of the valve. To remove the cap, unscrew it counterclockwise to reveal the metal pin.
Extract the metal pin
Removing the metal pin will deflate the tire faster by letting out all air at once. Extract the pin by grabbing it with the use of a needle-nose plier then rotate it counterclockwise.
Screw the metal pin back into the valve
Once you’re done letting all the air out of the tire, screw the pin back to the valve so you don’t misplace it.
How to let the air out of tires to the recommended air pressure
If you only need to let out just a fraction of air pressure on your over-inflated tires to their recommended level, you don’t need to lift your vehicle like the instructions above to do so. To let the air out of tires to the recommended air pressure, this fairly easy task will only require you to have a tire pressure gauge and an air compressor or inflator on top of a long, blunt tool to accomplish it safely and accurately.
- Tire pressure gauge
- Screwdriver or any thin, long blunt tool
- Air compressor or inflator
Find the valve stem
The first step, like the instruction above, is to locate the valve stem normally seated between the spokes of your wheels.
Ideally, you can work on the remaining steps easily if the valve is positioned at the bottom or at the lower sides, so if possible, move the vehicle forward or backward a bit in order to place the valve at the desired position.
Remove the cap to reveal the metal pin
Remove the cap by rotating it counterclockwise. You can then access the metal valve which includes a metal pin inside that will be used to adjust the air pressure.
Check the Air Pressure
Using a tire pressure gauge, attach the tip to the metal valve. Regardless of the type of gauge you use, the result can be read out in pounds per square inch, or PSI. Compare the result against the recommended air pressure. This is commonly listed on a sticker inside the driver-side door frame for newer cars. Alternatively, tire specifications can also be found in the owner’s manual.
Reminder: allow the tires to cool down first before you proceed with measuring the PSI to get accurate results since warm air tends to expand.
Press the metal pin using a thin, long, blunt tool
The most common tool you can find is a good old Phillip’s head screwdriver. Its long neck is suitable to get into the hard-to-reach valve faster and it has a blunt point to prevent damage to the valve, though, any similar tool is fine. You will hear a hissing sound as the air comes out of your tires.
Reminder to be careful enough not to apply too much force while pressing the pin as you may slip the tool and cause punctures or scratches to your tires or wheels.
Lift the tool off of the metal pin
You will just need to press the metal for a few seconds. Lift the tool off of the metal pin after a while, so as not to deflate the tire completely.
Have the air pressure checked again
Attach the tire pressure gauge again to check how much you’ve lost. You may have overdone the previous step and let out too much air, but don’t worry, you can just inflate it with an air compressor or inflator until you meet the recommended PSI.
Reminders when letting the air out of tires
Securely set the metal pin aside when extracted.
When letting the air out of your tires, keep the metal pin secured in a separate location. Keep in mind that you won’t be able to reinflate the tire again without this. The replacement may come in cheap but you’ll definitely spend time ordering.
The same thing must be done to the stem valve cap. Although a missing cap does not significantly contribute to faster air loss, the build-up of contaminants can damage the entire tire valve which could cause leakage.
Let the tires cool down first before checking tire pressure
A prompt action when you feel something is wrong is good, but this time, let your tires cool down for a moment. This is important because warm air causes particles inside your tires to expand, giving you false reading in the process. A general rule of thumb is to give at least an hour if the outside temperature is also high.
Tweaking your tires to let the air out of them is relatively easy to do, you just need to have the proper tool at hand, so you could have an accurate reading and work on this task faster.