Tire slowly losing pressure??

[NNT]

I got my tires from Costco last year. its been ok so far untill about 1 month ago, one of my front tire lose all the pressure and flat. I took it out and check and no puncture so I brought it back. they inspect it and claim nothing wrong, bascially they inflate it and left it for a few hours and the tire is holding up good, then they replace the valve steam and gave me the tire back. I put it back on and 2 weeks later, its flat again. I brought it back and bascially they did the same and ask me to see how it goes. I just leave in in my trunk without installing it. now about 1 week later, the tire pressure is dropped to less than 10 psi, so I am going to bring the tire back the 3rd time.
So what possibility might go wrong? I have a feeling they are going to inflate it and give it back to me.

[Soundy]

Probably leaking around the bead - check for a bent rim.

Do it old-school - find a container big enough for the whole thing to fit in, fill it with water with a good percentage of dish soap mixed in... put the tire in, weight it down so the whole thing is submerged... watch for bubbles.

[s300ae]

Or... get a spray bottle with soapy water, spray it around the bead, watch for bubbles.
no need to submerse entire wheel into water.

[Soundy]

No, but it's probably more efficient if it's a really slow leak, otherwise you might have to keep soaking it down, and it's harder to do two sides at once.

[Neva]

buy a new one

[NNT]

[QUOTE=Soundy;7894431]Probably leaking around the bead - check for a bent rim. [\QUOTE]

is there any fix if it is bent rim?

[NNT]

Originally Posted by Neva

buy a new one

new tire? I am pretty sure Costco would warrenty if they find anything wrong with the tire, the probelm is they couldnt.

[Bahhbeehhaaaa]

if you bought your tires from cos then bring it back to them and have them repair it!

[Neva]

Originally Posted by NNT

new tire? I am pretty sure Costco would warrenty if they find anything wrong with the tire, the probelm is they couldnt.

I doubt they would. What's a tire warranty anyway? If it's their fault and you come back the same day from leaky beads or stems then yes but not a year later after curbs, nails, rocks or whatever else.

You can try and bang out the wheel with a hammer to see if gets you anywhere if you find that there's a bead leak and after the wheel is cleaned up and bead sealer is used. My old shop used to do it occasionally for mystery bead leaks and sometimes it would work sometimes it wouldn't. Best bet is to either soak it down with really soapy water and wait for bubbles of dunk it and leave it till you see something. All the shop is going to do is the same thing they've been doing and will probably end up doing less and less each time you go back.

[NNT]

Originally Posted by Bahhbeehhaaaa

if you bought your tires from cos then bring it back to them and have them repair it!

if you read my whole post then you should know I am bringing the tire back, in fact already twice and the problem persist and they cant pinpoint the problem.

[Raid3n]

it's probably the bead that is leaking. you'll have to break the bead to apply the sealer. so best to let a shop do it.

[nickmak]

you're bead is leak. possibility maybe corrosion on rim? you driving aluminum rims? driving winter with aluminum rims no helpy either..

[narfy]

first things first... find the leak!

can't assume it's the valve stem, the bead, or whatever... could be a tiny puncture, could be a cracked rim... could be anything... soapy water in a spray bottle... soak the tread and look for bubbles.. then soak the beads and look for bubbles... if it's the bead, have the tire shop remove the tire, wire wheel the bead of the rim, and use seam sealant to glue the tire back onto the rim...

[fliptuner]

I agree w/ narfy.

Submersing in a tub would be ideal but 99% of the time you can find the leak with soapy water in a spray bottle. Most efficient way is to spray as you roll the tire (the tread, sidewall, valvestem, valve core, bead and even the inside of the rim). Move the valve stem around when it's wet.

In 18 years of doing tire work, I've only needed to submerse 1 tire to find a tiny, tiny leak. It's annoying to hear that you went to the shop twice and they didn't find the problem. If you want to come over to Coquitlam, I'll find the leak for you.

[G-spec]

^ hey flip good info, got a quick question for you... I'm runnin low pros 35 series up front on my 20's and I'm havin to fill them back up twice a month, both of my fronts are losing about half the air every 3 weeks or so, roughly two times a month I have to refill them, they usually end up somewhere around 15-20 psi, so that's about half the air I'm losing once or twice a month in both tires equally, I keep them both above 40psi

I'm assuming it's because they're low pros that are barely even stretched (255/35/20) and my suspension is very stiff so most of the shock absorption is done by the tires unfortunately.. Anyway that's my assumption because both of the tires lose almost identical amount of air at same time, so my question is, am I correct to assume this, or could it be something else ?
will do that soapy water test tomorrow btw

[fliptuner]

Has this been happening for a while now or just started? Remember that since they're such a low profile, there's not much air in there. You need the safety bead to be in excellent condition with stretched tires.

[G-spec]

no I've had the tires on since last year, this was the first winter they been through, and I know come winter time tire pressures go ape shit, but I'm still havin the same issue, I think it's because I put my coilover dampening to full stiff at the front of the car now....

yea I would call it a mild stretch, these tires run larger than true size, so this 35 series is almost like a 40 series so i highly doubt it's because of that.....
gonna test for leaks this week, doubt it though, then will try raising the car and putting my coil dampening back to softest setting....
although im probably gonna get lazy scratch all that and just buy new tires, they pretty cheap like $80 a pop for these nexens