Why Do All My Tires Keep Losing Pressure?

A loss of tire PSI is a normal issue that plagues car owners all over the country, from the cold upper depths of Wisconsin to right here in sunny San Antonio. More often than not, changes in temperature result in decreased tire PSI, and a simple Pfft from an air compressor solves the problem. If you see your tires losing pressure but there’s no leak, there could be an underlying issue that needs to be addressed. Here are a few of the more common reasons for a drop in tire PSI or why you may have a slow leak in your tires with the service experts at Northside Ford.

1. Wheel Bead Corrosion

Certain types of wheels, such as die-cast aluminum or magnesium alloy, are more prone to rust and corrosion. Any slow tire pressure leaks that aren’t easily detectable may be caused by a corroded wheel rim and bead seat.

How do corroded mag wheels lower tire pressure, you ask? When a rim and beading seat become damaged, the road vibrations can degrade the round shape of the wheel. As a result, your tires will be pushed into areas of the wheel that cause the side walls to degrade, as well. With a corroded wheel, tire air loss will gradually worsen as time goes on.

The typical solution when this happens is to replace your wheels. (By replacing just your tires, you’ll only be putting a Band-Aid on the problem, as those tires will need to be replaced earlier, too.)

However, if the damage isn’t too bad, it may be possible to remove the corrosion on the bead area with a Buzzy Wheel. If so, bead sealer should be used to ensure the damage is kept at bay. Either way, your tire service advisor or mechanic will be able to provide a more thorough explanation and set of solutions.

2. Valve Stem Failure

Unless you are filling up your tires or washing your car, do you ever notice your tire’s valve stems? Probably not. But did you know that tire valve stems can actually deteriorate over time? With road salts and other chemicals, the plastic and rubber on your car tire’s valve will become more brittle, resulting in slow leaks of air. (An overly tightened tire stem core may hasten the rate of deterioration, as well.)

Usually, when the problem is your tire valve stems, you’ll notice consistent air loss in all 4 tires. If this is the case, the solution is to purchase a new set of tires. However, preventative cleaning – that is, cleaning your car monthly, at the very least – can prolong the life of your tire valves.

3. No Valve Caps

Maybe someone stole one of your tire valve caps. If that’s the case, a 1- or 2-PSI drop per month may occur in that tire. Luckily tire stem caps are cheap and can be purchased at any auto parts shop or ordered at our San Antonio Ford Parts Department.

4. Tire Bead Damage

A poor sealing surface between your metal wheel and tire can result in minor or significant tire bead damage. Sometimes this is due to wheel corrosion (see #1) and other times it can be caused by debris that’s found its way into that wheel-to-tire sealing gap. When this happens, “bead chunking” is one visible outcome; that is, the bead on your tire will begin to tear or form dimples or pin-sized perforations. The other visible issue of bad tire beading is a broken seal, which is caused by weakened rubber and decreased elasticity.

In both cases, the damage to the tires has already been done. You will require new tires, and likely new wheels, as well.

5. Bad TPMS Kit

Ever see your TPMS warning pop up in the dash, only to discover that all your tires are already at the recommended PSI? Your vehicle may have a faulty TPMS, or tire pressure monitoring sensor/system. Some metallic tire pressure sensors are more apt to leak, especially over time.

Visit your auto service center for a full inspection and diagnosis. You may be in need of a replacement TPMS kit, which is affordable and can be installed by your service technician.

6. Tire Tread Puncture

Running over a nail or a sharp object can puncture the tire tread and inner liner, resulting in slight to major air loss daily. Some nails can remain in the tire for a short while without negatively affecting PSI, but removing it is still the best option, as leaving it in can lead to tread separation and, ultimately, a flat tire.

In this instance, the use of a tire plug or patch, alongside a full tire repair kit and sealant, maybe the fix. However, a tire service technician is 100% necessary to determine if this is an option. Repairing a punctured tire is not a DIY project!

7. Tire Sidewall Puncture

If your tire sidewalls are punctured, you will notice inflation pressure loss at an extreme rate. You will need a new set of tires.

8. Potholes or Curbs

San Antonio potholes are bothersome, to be sure, but they can also be downright disastrous to tires. Hitting a pothole or damaged curb will “flex” tire sidewalls, forcing them to lose a little air each time. Refilling the tire with air is usually all that’s necessary, but you should also check for any signs of tire damage after hitting a pothole, including sidewall bulging, slashes, or poor sealing.

See If There’s a Slow Leak in Your Tires at Northside Ford

If you’re unable to figure out what’s causing your tires to lose air or if you have a tire losing pressure but there’s no leak,  you should contact your mechanic or a certified tire service center in your area. At Northside Ford, the techs at our auto service and tire shop are ready to diagnose and fix your issues. You can find more helpful service tips and save on your next visit with our rating coupons and specials. Our dedicated parts team can repair simple tread punctures, re-align wheels, or install new tires. Contact our San Antonio Ford service center at (210) 525-9800 to speak with one of our experts, and we’ll have you in our repair bays – and back on the road – ASAP.