Very slow leak

Darwins Child

The passenger front tire on our '14 touring sport loses about 3 psi per month. This is not a great problem except that within two months, depending on when the first significant snowfall comes to Edmonton, I'll be backing our vehicle into our garage for its winter storage position -- the passenger side as close as possible to an outside wall.

If the tire goes flat over the winter, which may very well happen, I'd have a heck of a time getting an air line onto the tire valve and I might have to drive the vehicle forward a few feet to get access and I don't want to do that on a flat tire. (Would perhaps three rotations be a terrible thing to do?)

So today I took the wheel off the vehicle, increased the pressure from 32 psi (I had pumped it to 35 psi about a month ago) to 40 psi, and sprayed soap solution all over the tire's tread, bead area (with the tire lying down) and valve stem. In short, I could find no leak.

The tire has been plugged once at some point during its 9800 kms. I gave special attention to that plug with the soap solution and it does not appear to be leaking, but, again, this is a very slow leak and maybe it is so slow that soap solution will not detect it.

I'm now considering taking the wheel (which is still off the vehicle) to some tire place that has a dip tank, but I doubt if they're going to find the leak, either.

None of the other OEM tires has lost even 1 psi all summer. Do some tires allow air to permeate through the rubber?

Is there some new device that will "sniff out" a very slow leak in a tire?

Any advice on how to proceed would be welcome.

Thanks.

barncobob

I had a tractor tire, same thing, as a last resort I put a bottle of the green slime in and dammn if it didn't quit leaking.

Darwins Child

Because I've never heard of Green Slime, at first I thought you were joking, but then I found this:
https://www.youtube.com/watch?v=ZKdGfN_qiWQ

Coincidentally, the guy in the video was having a very slow leak similar to ours, but ours is even slower than his.

I have to wonder what happens to the slime inside the tire. In short, I'm pretty leery of this "fix". Does it just continue to slosh around in there for months or years, or does it more or less solidify over time? How does it affect the balance of the tire? Is the stuff very light in weight?

Thanks.

SouthArk370Z

I wouldn't recommend using Green Slime (or similar) in high-performance tires. Take it to a reliable tire shop and have them find/fix the leak.

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jchammond

with tire removed from ~Z~,
inflate to 5psi above max pressure (labeled on tire)
be sure tire is clean from dirt,rocks,grass,etc...
use only water flowing from a garden hose (very low flow)
find a starting point (valve stem) & slowly go over both sidewalls & then over tread;
the clean water will make small bubbles.
Perform this outside in the most light possible & you will find your leak.
I've had some pin-holes in the sidewall drive me crazy in the past & putting the tire in the tank of water would not expose it.
My Daughter's Fusion was losing 1lb. per week & turned out to be a pin hole in sidewall-near the shoulder.
Also ck. the wheel,,,could have a fracture in the Aluminum.

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TreeSemdyZee

You might try blowing the tire up quite a bit. 50psi or above. Let it sit for a few minutes and then let it back down. The bead might not be seated exactly right and your leaking slowly.
My right front has been leaking slowly for the past couple of years and I haven't figured out exactly why. Not as much as yours, but still leaking.
You might also check the valve core. I just bought a core tool to make sure mine was tight.

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Jsolo

I had a similar slow leak in one of my old tires. Took a good 20 minutes to find it. Nail was under the tread and not visible. Bubbles were the smallest I ever seen. If it's not a puncture then either valve core, valve stem, or rim bead leak.

Had a valve stem leak on a different car, valve hole had rust and stem was not sealing good any more.

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Darwins Child

Thank you all for your great suggestions. In particular, although I did examine the bead area very well (with the tire on its side so that that area was completely covered with soap solution), I did not pay that much attention to the side walls and I might have missed a pin-hole leak in that area.

As a next step, I've gotten my wife's permission to fill our bathtub with enough water to completely submerge the bottom portion of the upright tire/wheel, but not so much that it will "float" the tire. After waiting for a few minutes for the water to completely "quiet", I'll check for leaks (tilting the tire a bit to examine the sidewalls) and then, if necessary, rotate the tire so that a new portion is submerged. Etc.

I'll start off with the valve completely submerged, then the plug, then to the rest of the tire/wheel.

Luckily, I already washed the tire and rim very well yesterday, so it's not going to dirty the tub appreciably.

I have only one question at this point. What is the absolute maximum pressure to which this OEM Potenza tire can be inflated? The sidewall states "never inflate above 40 psi", but I believe this is advice about operating pressure, under load, at speed, hot, etc. This will be "just sitting there", and I want to find the leak, but I don't want to have the thing explode in the tub.

I'll report back what I find on this Reality TV nail-biter.

Thanks again.

Edit: What is the fix, if any, for a true pin-hole (not nail-hole) in the sidewall -- Green Slime time?

Darwins Child

The bathtub worked, but it was because of the clicking sound of the leak, not bubbles.

At some point right after a partial rotation, the bathroom was so quiet that I was able to hear a faint click, followed by another click maybe three seconds later, then another, etc.

To more isolate the click, I rotated the tire back into the water until the click stopped, then back out until I heard the click again. This pretty much isolated the relative position across the tread width. Then I rotated that portion of the tire to the topmost position and, finally, literally using a magnifying glass, I was able to locate the puncture, as shown in the photos below.

After that I plugged the hole using a plug-kit that I had purchased a few years ago to repair my daughter's tire.

I then pumped up the pressure to 35 psi and, using my grand daughter's very old blowing-bubble solution, carefully checked the plug for leaks. There were none, but I'll be checking tire pressure over the next few days and weeks to verify that I stopped the leak.

Now I don't have to worry about that tire going flat while in storage this upcoming winter. Great!

Thanks again for the advice.

(In the left-most photo I've pointed out the old plug and the tiny puncture, the latter of which is just below the right edge of the black tape, in the channel between treads. The middle photo has a zoomed-in view of the tiny puncture and, surrounding it, what looks to me like a round impression of a nail-head. The right-most photo shows the old plug and the new plug.)

Attached Images

	Tire leak 1.jpg (100.7 KB, 29 views)
	Tire leak 2.jpg (411.4 KB, 23 views)
	Tire leak 3.jpg (133.0 KB, 20 views)

barncobob

that tire has seen better days my friend, id replace it.

Jsolo

The plug should really be driven on to set properly. Tire needs a few heat cycles. But as mentioned, with two plugs that close together, replacement is the better option. Otherwise, you may end up resembling your screen name

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TreeSemdyZee

...and then his wife beat the crap out him for leaving a ring in the tub.

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Fuzzzy

Reminds me of my lawnmower tires a couple months after having my house re-roofed about ten years ago.

But I wasn't driving it at highway speeds.