Overfilling your tires is easy to do, and if you drive on tires with too much air, then your tires will suffer from uneven treadwear in the center of the treads. On the other hand, if your tires don’t have a sufficient amount of air pressure, they’ll wear out on the left and right sides of the tire treads.
Keeping your tire air pressures at the correct PSI is vital to drastically increase the life of your vehicle tires by reducing tire wear.
Did you over-fill your tires with air while DIY? If so, before you do let the air out of a tire, read this quick guide to help you learn everything you need to know:
What You Need To Know About How To Let Air Out Of A Tire
Sure, higher than normal tire pressures is more fuel economical, but it can also cause dangerous handling issues and unnecessary hydroplaning. Not to mention the price of new tires these days.
Letting air out of car tires and using a tire pressure gauge is the easiest thing ever. Educate yourself on how it works so you don’t end up looking like an idiot in front of other people.
Letting Air Out Of A Tire (3 Different Methods)
Keep these in mind the next time you’re dealing with tire inflation issues. Here we cover the different methods, then down below we go step by step:
Method One: Press down on the pin
The easiest way to remove air is by simply removing the valve stem cap and pressing on the pin that sits flush in the middle of the valve body. This lets the air out in a slower and more controlled fashion for precision PSI tuning.
Method Two: Unscrew the valve stem/valve core
Removing the valve core from the valve body is done simply by unscrewing it from the middle. Look down past the metal pin, and you’ll notice there are two empty spaces shaped like half circles. Use a valve stem remover or even a set of needlenose pliers to unscrew the valve body.
Method Three: Puncture the tire
The last method is simply puncturing the tire, and there are random situations where someone might simply slash the tire with a switchblade rather than safely let the air out of the valve (be nice to your ex).
For example, a junkyard worker might simply crush a car with a machine and let the tires explode rather than wasting time removing each valve core.
How does air escape from tires?
Flat tires are a total drag. The best way to see exactly where the air is escaping from a leaking tire is by either submerging the tire and wheel completely in water or spraying it down with a mixture of soap and water. You might also hear hissing sounds coming from the tire.
Here are a few different ways air can escape from your tires:
Air leaking from the bead seal
It’s common for tires to lose air from where the tire meets the wheel. Sometimes cars have this recurring problem (cars with chrome wheels, for example). The solution to this problem is to remove the tire from the wheel and resurface the corroded metal with a circular metal brush attached to a drill.
Air leaking from a loose valve stem
Sometimes the reason why your tire is leaking is simply that the valve stem has become slightly unscrewed. Always stick some needlenose pliers or your valve stem tool into the valve and give it a firm tightening torque before proceeding to search for tire punctures.
Air leaking from a puncture
Tire puncture is probably the most common car maintenance issue. Always check for obvious signs like screws/nails if you’re constantly having to fill your tires up with air.
Also, don’t be intimidated by your tire maintenance; it’s not as hard as it seems. Just remember, if your TPMS system or pressure measurement says there’s too much air in the tire, there are a million different skinny objects you can stick into that tire valve to let a bit of air out.
How Does A Schrader Valve Work?
The Schrader valve is a spring-loaded valve that has an externally (and internally) threaded hollow cylindrical tube. After unscrewing the cap, you’ll see a metal pin running through the center of the valve that runs through the entire valve.
This metal pin that you push in to let the air out is part of the spring-loaded valve stem, or valve core that screws into the center of the cylinder to create a controlled pressure environment on the opposite side of the valve.
So, if you want to slowly let the air out of a tire, you press the pin with virtually anything that will fit (flathead, needle nosers, a hairpin, a pen, etc).
But if you want to let the air out quickly without puncturing the tire itself, you must unscrew the Schrader valve stem (to the left) and completely remove it leaving an empty cylinder.
Watch this video to see exactly what happens when you let the air out of a tire:
Schrader Valve vs Presta Valve
What’s the difference between Schrader valves and Presta valves? First, Schrader valves have spring retention that makes them sturdier—they hold the air in better.
Presta valves have a valve core retention nut that slightly unscrews to let the air out of the valve. There’s no spring in the design. Some bicycle tires still use Presta valves because of their skinny shape and easy-to-inflate design, but they’re not sturdy enough for automotive or HVAC use.
Schrader valves are also much easier to service—you’re technically not supposed to be able to remove the valve core on a Presta valve, and even if you do unscrew the retention nut all the way, the valve assembly will only exit through the back side (inside the tire).
Air compressors are nice to have around
What, you thought you were going to pump up your tires with the tire pump for bicycles? Unfortunately, bike pumps don’t do the trick when inflating car tires that haven’t been lifted off the ground with a jack. You would need to remove the wheel to sufficiently inflate your car tire with a bike pump, and even then it takes too much huffing and puffing.
In the maintenance shop, automotive technicians always have an air compressor on-hand to assist in refilling tires with air among other things.
Garage air compressors
The air compressor is one tool that will survive the ever-changing electric car revolution. I recommend a 3-10 gallon air compressor for your garage.
In-car tire inflator kits
If you don’t already have one, I highly encourage you to buy a tire inflator kit and a tire plug kit in case of an emergency. Fixing some tire punctures is easier than you might think.
Other Tire Safety Guidelines
For example, if you overinflate a tire it will explode and potentially send shrapnel everywhere. Granted, you would have to put 200 PSI + in the tire for that to happen, but it’s still very possible.
The real danger of overinflated tires is loss of control while driving. Sure, you might be achieving incredible fuel economy by overinflating your tires to 60 PSI instead of 40 PSI, but overinflated tires significantly decrease handling control around corners and on wet surfaces.
You should also know how to safely replace your flat tire with the spare.
Supplies You’ll Need For Taking Air Out Of Tires
Here’s the shop foreman’s list for taking the air out of tires:
Flathead screwdriver/Ballpoint pen
The super tool of choice in this instance is the valve stem remover/flathead screwdriver that Snapon guys give out for free when they come around to auto shops.
All in all, you just need to know how your tire valve works for a better idea.
Needle-nose is another great tool that can versatile remove air from the tire and also completely removes the valve stem when needed.
Valve stem remover
A flathead screwdriver of the correct diameter will also fit into the valve to allow you to unscrew it. Check Amazon or your local auto parts store to buy one of these.
Tire pressure gauge
Keeping a tire pressure gauge in your glove box is essential. Tire gauges are so simple and cheap, and measuring your tire pressures every month or so really does help reduce uneven treadwear and poor fuel economy.
Emergency tire repair kit
I always recommend keeping a fix-a-flat kit in your car with you at all times.
Tire chuck/Tire inflator with gauge (optional)
As a professional, I use a tire inflator tool that lets me both inflate and deflate the tires with two different buttons, and it also gives me the PSI reading in digital format.
5 Simple Steps To Letting Air Out Of Tires
- Unscrew/Remove the valve cap
- Check the PSI using a tire pressure gauge
- Inflate or deflate the tire to match PSI spec
- Replace valve cap
- Verify success & reset the TPMS light
Step 1: Unscrew/Remove the valve cap/Remove valve stem (if necessary)
If the valve has a valve cap, you’ll need to take that off first. Lefty loosey, as they say.
If you need to empty the tire of air, the fastest way (other than slashing the side of the tire) is by using a valve stem remover tool/valve stem puller.
Step 2: Check the air pressure (PSI) using a tire pressure gauge
The idea is to firmly press the tire pressure gauge into the valve at a perfectly straight fit like you’re sliding the first beer into your koozie after a long day’s work.
If you don’t stick the gauge in straight and hold it firm, then you’re not going to get a very accurate reading. Some Schrader valves have a rubber stem that causes them to bend. With the flexibility of the tire valve in mind, make sure you’re getting the gauge completely onto the valve to the point where the valve is completely opened. Ideally, no air is coming out—this means the full force of pressure is acting against the tire pressure gauge for an accurate reading.
Step 3: Inflate or deflate the tire to match the pressure level to the PSI spec
Look on the driver’s side door panel of your car, and you’ll find the recommended tire pressure for front and rear tires printed somewhere in the factory labels.
It’s also important to know when to slightly overinflate or slightly underinflate tires. For example, if you’re always driving in snow, there’s no problem lowering the PSI from 36 to 31. It will increase traction on wet surfaces.
If the conditions are dry and not too extreme, there’s nothing wrong with going ~5 PSI over the recommendation to help increase fuel economy.
Step 4: Replace the valve stem cap
Replacing the valve stem caps is important because they protect the valve from dirt and corrosion.
Before you replace the valve cap, it’s always okay to quickly check if the valve stem is firmly screwed in. Since the actual valve stem can come loose due to vibrations, this is another reason why tires go flat in the first place.
You might think you have a tire puncture, but it could be a problem as simple as a slightly unscrewed valve stem.
Valve stem remover tools are so clutch.
Step 5: Verify success and reset the TPMS light on the dash (if necessary)
As a technician, I always drive the car around for 10 miles or so to make sure air isn’t escaping from the tires.
Your tire pressure monitor system may or may not immediately recognize that you’ve adjusted the air pressure to spec. Some cars recognize air pressures immediately, some need to be reprogrammed using the steering wheel/dash controls, and some cars simply don’t have a TPMS system.
Videos always help simplify things:
Other Valuable Resources On How To Let The Air Out Of A Tire
I like to fill my tires with nitrogen. Nitrogen molecules have a larger diameter compared to oxygen which helps prevent air from escaping. Plus, nitrogen molecules are also lighter than oxygen molecules, so it prevents flat spots and other poor tire performance.
Underinflated tires cut fuel efficiency/gas mileage and create uneven treadwear, and over-inflation also causes uneven treadwear/reduces driving experience by reducing handling control. That’s why you should be religious about properly inflated tires.
Check tire pressures constantly, and if you’re going to DIY your car, make sure you do it correctly!