[tire]very slow leak...help
Thread Starter
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
[tire]very slow leak...help
A week ago I discovered my LR was flat; it's a GY Eagle HP Ultra Plus 275/40ZR17.
I took it to a shop where they did the usual dunk test and replaced the valve core. I mounted the tire onto the Vette in early evening and by next morning it was flat again.
Subsequently I took inflated the tire to 45psi and personally went over it with soap bubbles (the rubber, the valve stem and even the metal of the wheel) and could not find any leak. Even close inspection with a very strong light and magnifies could reveal no problem spot.
Two days ago I inflated it to 45psi and left it in the hatch of the IROC-Z for 48hrs; this morning I checked pressure and found it at 41psi. Air temp was about the same on each day.
I dropped the pressure to the normal driving pressure of 33psi and intend to check again in 48hrs.
I'm really stumped as to what could be the problem; it's very difficult to leak test with such a slow leak.
Anyone have any suggestion as to how to diagnose this problem??
I took it to a shop where they did the usual dunk test and replaced the valve core. I mounted the tire onto the Vette in early evening and by next morning it was flat again.
Subsequently I took inflated the tire to 45psi and personally went over it with soap bubbles (the rubber, the valve stem and even the metal of the wheel) and could not find any leak. Even close inspection with a very strong light and magnifies could reveal no problem spot.
Two days ago I inflated it to 45psi and left it in the hatch of the IROC-Z for 48hrs; this morning I checked pressure and found it at 41psi. Air temp was about the same on each day.
I dropped the pressure to the normal driving pressure of 33psi and intend to check again in 48hrs.
I'm really stumped as to what could be the problem; it's very difficult to leak test with such a slow leak.
Anyone have any suggestion as to how to diagnose this problem??
Pro
Joined: Apr 2008
Posts: 542
Likes: 0
From: middle of Illinois
My thoughts:
If it's new, take it to whoever installed it in the first place and have them pull if off the bead and put it back on. It will need balanced again, too. If they're a reputable shop, they shouldn't charge for re-doing their work to get it right.
If it's been on there a few years, take it to any tire shop and have them do the same. They'll probably charge a few bucks.
If it's worn out or nearly worn out, buy new tires and have them installed.
If it's new, take it to whoever installed it in the first place and have them pull if off the bead and put it back on. It will need balanced again, too. If they're a reputable shop, they shouldn't charge for re-doing their work to get it right.
If it's been on there a few years, take it to any tire shop and have them do the same. They'll probably charge a few bucks.
If it's worn out or nearly worn out, buy new tires and have them installed.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
A week ago I discovered my LR was flat; it's a GY Eagle HP Ultra Plus 275/40ZR17.
I took it to a shop where they did the usual dunk test and replaced the valve core. I mounted the tire onto the Vette in early evening and by next morning it was flat again.
Subsequently I took inflated the tire to 45psi and personally went over it with soap bubbles (the rubber, the valve stem and even the metal of the wheel) and could not find any leak. Even close inspection with a very strong light and magnifies could reveal no problem spot.
Two days ago I inflated it to 45psi and left it in the hatch of the IROC-Z for 48hrs; this morning I checked pressure and found it at 41psi. Air temp was about the same on each day.
I dropped the pressure to the normal driving pressure of 33psi and intend to check again in 48hrs.
I'm really stumped as to what could be the problem; it's very difficult to leak test with such a slow leak.
Anyone have any suggestion as to how to diagnose this problem??
I took it to a shop where they did the usual dunk test and replaced the valve core. I mounted the tire onto the Vette in early evening and by next morning it was flat again.
Subsequently I took inflated the tire to 45psi and personally went over it with soap bubbles (the rubber, the valve stem and even the metal of the wheel) and could not find any leak. Even close inspection with a very strong light and magnifies could reveal no problem spot.
Two days ago I inflated it to 45psi and left it in the hatch of the IROC-Z for 48hrs; this morning I checked pressure and found it at 41psi. Air temp was about the same on each day.
I dropped the pressure to the normal driving pressure of 33psi and intend to check again in 48hrs.
I'm really stumped as to what could be the problem; it's very difficult to leak test with such a slow leak.
Anyone have any suggestion as to how to diagnose this problem??
I've found that some valve stems do not seal well against the rims well on these shiny applications and if you go to tighten the valve core the entire valve stem just spins in the rim instead of tightening the internal core seat.
If your's is spinning....try holding the valve stem with a pair of channel locks loosely and tightening the valve core again. Air it up again and check it for loss in a few days.
If you still have a problem remove the tire and valve then clean/inspect the rim, valve and the tire for damage on the mounting/contact surfaces.
Thread Starter
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Though they have been in service a few years, there seems to be ample tread left above the wear indicators for another season or two.
The wheels are OEM '89-style painted white (35th Anna) and the valve stem didn't seem to rotate when the tire was flat.
Looks like the consensus is to have a shop dismount and inspect the tire, sort of what I was expecting. It's just so frustrating to not be able to locate the damn leak...
Thanks for the feedback.
The wheels are OEM '89-style painted white (35th Anna) and the valve stem didn't seem to rotate when the tire was flat.
Looks like the consensus is to have a shop dismount and inspect the tire, sort of what I was expecting. It's just so frustrating to not be able to locate the damn leak...
Thanks for the feedback.
Last edited by 65Z01; Jan 27, 2009 at 02:35 PM.
Burning Brakes
Joined: Jun 2005
Posts: 1,191
Likes: 15
From: Wallingford Vermont
Pick up some "Tire Leak Detector" at the auto parts store. It's like your soap but better. Soap tends to put bubbles everywhere on the tire, then you have to spot the moving or growing ones to find your leak. The leak detector doesn't bubble as easy until it comes into contact with that elusive leak.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Pro
Joined: Mar 2008
Posts: 579
Likes: 2
From: High Bridge New Jersey
You
A week ago I discovered my LR was flat; it's a GY Eagle HP Ultra Plus 275/40ZR17.
I took it to a shop where they did the usual dunk test and replaced the valve core. I mounted the tire onto the Vette in early evening and by next morning it was flat again.
Subsequently I took inflated the tire to 45psi and personally went over it with soap bubbles (the rubber, the valve stem and even the metal of the wheel) and could not find any leak. Even close inspection with a very strong light and magnifies could reveal no problem spot.
Two days ago I inflated it to 45psi and left it in the hatch of the IROC-Z for 48hrs; this morning I checked pressure and found it at 41psi. Air temp was about the same on each day.
I dropped the pressure to the normal driving pressure of 33psi and intend to check again in 48hrs.
I'm really stumped as to what could be the problem; it's very difficult to leak test with such a slow leak.
Anyone have any suggestion as to how to diagnose this problem??
I took it to a shop where they did the usual dunk test and replaced the valve core. I mounted the tire onto the Vette in early evening and by next morning it was flat again.
Subsequently I took inflated the tire to 45psi and personally went over it with soap bubbles (the rubber, the valve stem and even the metal of the wheel) and could not find any leak. Even close inspection with a very strong light and magnifies could reveal no problem spot.
Two days ago I inflated it to 45psi and left it in the hatch of the IROC-Z for 48hrs; this morning I checked pressure and found it at 41psi. Air temp was about the same on each day.
I dropped the pressure to the normal driving pressure of 33psi and intend to check again in 48hrs.
I'm really stumped as to what could be the problem; it's very difficult to leak test with such a slow leak.
Anyone have any suggestion as to how to diagnose this problem??
Melting Slicks
Joined: Feb 2006
Posts: 2,753
Likes: 15
From: backwoods upstate ny
common prob with all alum wheels after a few years with tire mounted, even if never driven in salt/rain, is corrosion at the bead and where the valve core body meets the wheel...air leakage may occur over a wide area, making detection difficult...best fix is to remove tire and valve core body and polish contact surfaces (do not use a wire brush for any but temporary repair)...worst fix is "glue" that many tire shops apply to all alum wheels that they touch.
gilette "foamie" shaving cream, or = , will bubble up at leaks that soap won't show.
gilette "foamie" shaving cream, or = , will bubble up at leaks that soap won't show.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
When a tire on both my 96 and my son's 96 developed very slow leaks (different times), I increased the air pressure to the MAX then sat each in my bath tub, full of water.
After a minute or two, I saw the bubbles.
Jake
After a minute or two, I saw the bubbles.
Jake
