Why does a fully inflated tire lose air after a few days?
2 Answers
The reasons why a fully inflated tire loses air after a few days are: damage to the tire sidewall and inner edge; foreign objects puncturing the tire; deformation of the wheel rim flange; wheel rim cracking; damage to the tire valve. Damage to the tire sidewall and inner edge: The sidewall of the tire can wear out from rubbing against the curb. Damage to the inner edge of the tire usually occurs during improper installation or removal of the tire from the wheel rim, often seen when replacing a new tire or reinstalling a tire after repair. Foreign objects puncturing the tire: Nails, screws, wires, glass fragments, sharp stones, and tile pieces can easily puncture the tire. Nails and screws are particularly prone to piercing the tire, causing slow leaks. If left unremoved, they can worsen the damage to the tire. Deformation of the wheel rim flange: When the tire is fully inflated, the outer edge of the tire tightly fits against the wheel rim flange. If the wheel rim flange is deformed due to impact, it can compromise the seal between the tire and the rim, leading to slow air leaks. Wheel rim cracking: This is a relatively rare occurrence. It can cause the internal air of a tubeless tire to leak through the cracks. Small cracks can also become potential hazards for wheel rim fractures. Although rare, this situation is highly dangerous. Damage to the tire valve: If no abnormalities are found on the tire, check the valve. Most household cars are equipped with tubeless tires, where the valve is mounted on the wheel rim and is usually made of rubber. Over time, the rubber valve can deteriorate due to exposure to sunlight, rain, and internal tire pressure, becoming brittle and eventually cracking, leading to air leaks.
The tires were fully inflated but lost air after a few days. I've encountered this phenomenon while using the car, and I believe the main reason is that the tire has a slow leak. The most common causes are nails or small stones stuck in the tread that haven't completely fallen out, leading to a gradual loss of air; or the valve stem may be aged or damaged, resulting in poor sealing and slow air leakage. Additionally, scratches or rust on the wheel rim edges can cause poor contact with the tire, creating small gaps for air to escape. Checking it yourself is simple: after parking, spray soapy water on the tread and valve stem, and observe where bubbles form—that's the leak point. A leak is dangerous; low tire pressure can lead to a blowout or increased fuel consumption, so it's recommended to visit a professional tire shop for repairs as soon as possible. For regular maintenance, avoid sharp road surfaces and check tire pressure at least once a month to ensure it's within the standard range.
