Flat tire right after replacing all tires - what could be the cause?

Question

We just had all 4 tires replaced, a week after we got a flat tire. In the past several years not a single flat tire.

The cost of each tire was $55 (with labor I paid $409). The car is a Honda Civic 2007 Hybrid. The tire model says LEAO / LION SPORT GP.

The Mechanics said he put air and he does not find any leaks, he did put the tire in water and no bubbles came out. We have been driving the car for a few days now, and so far there is no sign of any leaks.

I should also mention that I heard some noises right after replacing the tires, and I checked and did not see any issue with them, and only after a week, suddenly a flat tire.

I'm not an expert about cars but my logic mind assumes that the tire was not fully or correctly assembled when replacing the tires. Could that be the cause?

UPDATE - 8 MONTHS LATER

Tires still have no issues. This means it has to be incorrect first assembly, which was fixed on the second assembly.

Answer 1

It's unlikely to be the tyres themselves at fault - if it's not down to external causes (e.g. a nail), it's more likely to be either damage to the wheel rim stopping the tyre from sealing properly, or a dodgy valve letting the air out.

Either way, after just a week you ought to be able to take it back to the dealer who fitted the tyres and they ought to sort it for you...

Answer 2

I know the mechanic filling the tire back up said he didn't find any leaks, but the air had to go somewhere. Assuming that the tire was correctly inflated when they were installed, the real question is where did the air leak from? The three likely possibilities are:

1) The valve stem

It's possible whoever changed the tires didn't use new valve stems and/or valves. They're located in the rim of the wheel, so it's entirely possible that they were overlooked. They can become brittle and crack with age, just like tires, and should be replaced at every tire change. The valve could also be leaking, especially if it doesn't have a protective cap and has been exposed to the elements.

2) The seal between the tire and the rim

This is an especially high possibility if you have steel rims and/or corrosion. The corrosion will create an uneven surface that will continue to deteriorate, allowing air to escape where the surfaces meet. In either case, a lubricant such as soapy water should be used liberally when mounting the tire. This will ensure the tire slides into place smoothly without damaging the inner lip of the tire, creating a good seal.

3) There is leak somewhere in the tire

Maybe it's a manufacturer defect (unlikely), or maybe you were just really unlucky and got a puncture. Punctures are less likely with the thick tread of a new tire, but they're still a possibility.

Going forward you need to keep an eye on the tire and see if it's losing pressure, and at what speed. You can try spraying the tire with soapy water. Any air escaping will create bubbles and be easier to pinpoint. If the leak is slow enough that it's taking a day or two to go flat, this might not work. In that case, I'd be leaning toward the seal at the rim. If the valve stems haven't been changed, consider having them changed.

Answer 3

If there are no leaks, and if you were not driving the car when the tire went flat. The first thing comes to mind is a prank. Somebody emptied your tire! You should fill it up and keep an eye on it and see if it goes empty again.

But if it happened when you were driving, it may happen with very hard braking or acceleration if the tire pressure was too low to begin with. Many times shops put a little mark next to the valve stem to see if the tire was moving on the rim (if it moves it means it did not have a tight enough seal with rim). Tyre damage: Causes and avoidance See page 11:

Low tyre pressures can reduce the safety when 
negotiating corners. The tyre bead may be 
torn away from the rim and slip from the rim 
flange down into the well base. The result is a 
sudden loss of air pressure in the tyre. 

You did not tell how your mechanic checked the tire for leaks. Is your mechanic 100% sure? or could he/she be mistaken?

Because you did not tell the exact circumstances which lead to the flat. It may be impossible to answer your question. What were you doing exactly when the flat occured? ( I will update my answer if you update your question :) )

Answer 4

Throwing this out there as a possibility: There is something jammed in your tire, but unless the tire is under load the foreign object is doing a good enough job plugging the hole. Its stabbed in someplace hard to see, or deep enough that it isn't even visible anymore.

On the day it went flat, it happened that the tire was loaded in such a way that the hole was flexed and the foreign object was no longer a good seal. When they place this tire in a water tank, there is no load and the nail/drill bit/whatever is holding it shut.