Slow leak caused by corrosion at bead on alloys?

Some more insight into bead sealing:

Typically, the bead diameter is SMALLER than the wheel diameter in that area of the tire.

Further, the bead is designed with an angle GREATER than the bead flat of the wheel. That's 2 ways the sealing is supposed to take place.

What that means is IF someone were to grind off some of the wheel in that area (like if you were to remove ALL the corrosion down to bare metal!) the tire might not seal. Remember the bead is a circle and grinding in that area means the rubber has to fill the gap.

On top of that, the radius of that "corner" (where the flat of the bead meets the flange) is LARGER in the tire than the wheel - meaning it CAN'T seal there. They do that to make sure the bead doesn't hang up there and not fully seat on the wheel.

Now allow me to address bar codes:

First, it isn't the bar code that is causing the leak. It's that the leak is occurring somewhere else and finds the barcode the easiest place to escape - making it look like the bar code is leaking. Moving the bar code isn't going to prevent the leak.

Why do they put it there? Because if they put it inside it will be covered up by the lube they spray inside, and if they put it on the outside, it will be covered by the lube that is sprayed on the outside. The bead area is the only area where lube is NOT sprayed.

So why do they spray lube on the inside and outside? To help the tire release from the mold and because the lube is slightly textured, it helps prevent molding flaws and trapped air.
 
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What that means is IF someone were to grind off some of the wheel in that area (like if you were to remove ALL the corrosion down to bare metal!) the tire might not seal. Remember the bead is a circle and grinding in that area means the rubber has to fill the gap.

I did wire wheel to bare metal!

So, in my case, I should apply bead sealer on the seal part of the tire (after squeezing the tires into the rims)? OR not, since most of the bead sealer would be wiped off while inflating with air (and tires pops into its' place)? OR, since the tires are brand new, it would have forgiving seal capably to reseal those beaten areas from wire wheeling? Just install the tires (lining up the red dots) and hope for the best? I just don't want to expect slow leaks in few years later (but many cars are like that anyways, no matter what).
 
I don't know how the barcode sticker would not be the source of the leak, because when you remove the sticker the leak stops. I think that flat area where they put it also moves around a little while the tire goes around too. You can even see the outer edge of the flange wearing down from friction on some wheels. The tires with the thick curb protectors ride on the edge of the wheel flange.
Not all tires with stickers leak, but some do especially the ones not stuck on really good. I see a lot of them loose, and just fall off when the tire is removed. Even the OE tires.
I'm not the only one that has seen this issue.
https://www.moderntiredealer.com/blogpost/lori-s-listening/340186/dealer-says-move-those-barcodes
 
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Originally Posted by Traction
I don't know how the barcode sticker would not be the source of the leak, because when you remove the sticker the leak stops. I think that flat area where they put it also moves around a little while the tire goes around too. You can even see the outer edge of the flange wearing down from friction on some wheels. The tires with the thick curb protectors ride on the edge of the wheel flange.
Not all tires with stickers leak, but some do especially the ones not stuck on really good. I see a lot of them loose, and just fall off when the tire is removed. Even the OE tires.
I'm not the only one that has seen this issue.
https://www.moderntiredealer.com/blogpost/lori-s-listening/340186/dealer-says-move-those-barcodes


The real issue is that air is getting to the bar code location in the first place. It never should. The pressurized air in the tire is supposed to be held in by the sealing surface at the toe, on the flat of the rim next to the safety hump. So, when you removed the bar code and the leak stopped, the tire must be sealing at that location, but it's not sealing where it should be.
 
Originally Posted by jjjxlr8
Originally Posted by Traction
I don't know how the barcode sticker would not be the source of the leak, because when you remove the sticker the leak stops. I think that flat area where they put it also moves around a little while the tire goes around too. You can even see the outer edge of the flange wearing down from friction on some wheels. The tires with the thick curb protectors ride on the edge of the wheel flange.
Not all tires with stickers leak, but some do especially the ones not stuck on really good. I see a lot of them loose, and just fall off when the tire is removed. Even the OE tires.
I'm not the only one that has seen this issue.
https://www.moderntiredealer.com/blogpost/lori-s-listening/340186/dealer-says-move-those-barcodes


The real issue is that air is getting to the bar code location in the first place. It never should. The pressurized air in the tire is supposed to be held in by the sealing surface at the toe, on the flat of the rim next to the safety hump. So, when you removed the bar code and the leak stopped, the tire must be sealing at that location, but it's not sealing where it should be.


So having spent some time chasing this down, I'll give you what I found.

First, most tires are mounted on used wheels. In order to get the tire to mount completely and smoothly seat, mounting lube needs to be put on both the tire and the wheel - and plenty of it. Almost 100% of the time, not enough lube is used and the wheel is usually ignored.

How do I know this? Because we've measured tires mounted on wheels and were able to reduce the RoadForce values by half, just by relubing the mounting surfaces. (No, I am NOT talking about reorienting the tire on the wheel. I'm talking about deseating the tire and applying lube to the wheel in the bead area.)

Further, the company I worked for had some plants that used bar codes (as a pilot project) - and we did indeed hear that sometimes tires leaked at the bar code. sticker - BUT - we were never able to verify this. When we mounted the tires in question, we didn't get a leak. Couple that with the fact that the tire is designed to seal on the bead flat and not at the flange - AND that we can get a better fit by remounting the tire - AND the reports of removing the bar code also involve remounting the tire, we came to the conclusion that the bar code was not the source of the leak.
 
The barcode won't leak initially, but a year or 2 later they might as the tire moves around. As far as tire lube, I use the liquid blue lube on the upper bead and demount head removing the tire. When installing the tire I use the white mounting paste applied to the whole tire bead area, and mounting areas of the wheels. Then inflate to seat the beads, deflate and fill them to pressure, then RF balance. Not all tires have the same fit to the wheel. Some tires seat with only 10psi, and then others can be 40psi, and then there are once and a while where it take up to 80psi to seat not matter how much lube you use. I'm guessing the really tight fitting tires will never have a bead leak though.
 
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Originally Posted by Traction
The barcode won't leak initially, but a year or 2 later they might as the tire moves around. …….


Very interesting.

May I suggest the next time you encounter a tire that is apparently leaking at the bar code sticker, you debead the tire, but not take it off the rim - then relube and reseat the bead. If it still leaks there, then that would add another data point - and while it wouldn't eliminate the possibility that the leak is occurring elsewhere and still finding the bar code sticker, the opposite would help say otherwise.

Originally Posted by Traction
…… As far as tire lube, I use the liquid blue lube on the upper bead and demount head removing the tire. When installing the tire I use the white mounting paste applied to the whole tire bead area, and mounting areas of the wheels. …….


We used Ru-Glyde for everything.

One little side note: We had a set of wheels that we used to verify tires returned for balance and uniformity. They had been screened to have zero runout and we carefully balanced them to require zero weight. That way we could immediately tell what the RoadForce and balance values were directly. Those wheels had been used so often that they almost didn't require any lube - unlike wheels taken off cars from the fleet..

Originally Posted by Traction
……. Then inflate to seat the beads, deflate and fill them to pressure, then RF balance. Not all tires have the same fit to the wheel. Some tires seat with only 10psi, and then others can be 40psi, and then there are once and a while where it take up to 80psi to seat not matter how much lube you use. I'm guessing the really tight fitting tires will never have a bead leak though.


I hope I don't have to remind you that using over 40 psi to seat a bead comes with some risk. We've conducted experiments (as did other tire manufacturers) to see what pressure caused the beads to break, and that's where that value comes from. People have been killed when a bead breaks, so I strongly advise against using more than 40 psi.

Now about tight fitting tires not having bead leaks: I've found that bead leaks are either a "didn't completely seat" problem, or a "flaw in the sealing mechanism" problem. That is, the bead either got hung up (and I would think tight fitting beads would be more problematic), or there was corrosion, or dirt, or a crack, or a flaw in the bead of the tire, that allowed air to leak past the bead.

I've even seen wheels that were too small in diameter. I've also encountered circumstances where I couldn't find the problem.

Another side note: To try to figure out if the contour of the bead rings that we were using didn't have some issues we weren't aware of, we took a wheel and carefully cut slots in the bead area so we could see how well the tire fit onto the rim. We verified that the radius of the bead was not contacting the rim
 
As far as bead seating, I'm well aware of the 40psi warning, but what else can you do when it refuses to go on no matter what you do? I can't just give up, and hope the customers old tires will go back on. Pretty much have to stand a long ways away behind something, and hope for the best. I hate to even say that I have had a few that wouldn't go until over a hundred psi, and that is pretty scary, but it got the job done. Yes I should use a cage, and that looks scary too.
 
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