finding a fast "slow leak"



C

catzz66

Guest
Are there any tricks to finding a pesky tube leak? Tire goes completely
flat over a period of days. I replaced the tube and have the old one
off the bike. Tires are kevlar belted and there does not seem to be an
obvious leak in the tube. I have dunked the tube in water already.
 
R

Ralph

Guest
Windex - look for bubbles

"catzz66" <[email protected]> wrote in message
news:[email protected]
> Are there any tricks to finding a pesky tube leak? Tire goes completely
> flat over a period of days. I replaced the tube and have the old one off
> the bike. Tires are kevlar belted and there does not seem to be an
> obvious leak in the tube. I have dunked the tube in water already.
 
On Wed, 06 Sep 2006 14:15:13 -0500, catzz66 <[email protected]>
wrote:

>Are there any tricks to finding a pesky tube leak? Tire goes completely
>flat over a period of days. I replaced the tube and have the old one
>off the bike. Tires are kevlar belted and there does not seem to be an
>obvious leak in the tube. I have dunked the tube in water already.


Dear Cat,

I use the kitchen sink, since it's wide and there's good light.

Try inflating the tire more, since the greater pressure and expansion
help to reveal tiny leaks.

And try wiggling the valve stem. Sometimes a tiny crack near the valve
stem won't show up with low pressure until you help it a little by
tipping the valve to one side.

Cheers,

Carl Fogel
 
M

Michael Warner

Guest
On Wed, 06 Sep 2006 14:15:13 -0500, catzz66 wrote:

> Are there any tricks to finding a pesky tube leak? Tire goes completely
> flat over a period of days. I replaced the tube and have the old one
> off the bike. Tires are kevlar belted and there does not seem to be an
> obvious leak in the tube. I have dunked the tube in water already.


Pump the tube up to twice its flaccid width - that makes the hole
much bigger, and puts more air pressure behind it.

--
Home page: http://members.westnet.com.au/mvw
 
D

dvt

Guest
[email protected] wrote:
> On Wed, 06 Sep 2006 14:15:13 -0500, catzz66 <[email protected]>
> wrote:


>> Are there any tricks to finding a pesky tube leak? Tire goes completely
>> flat over a period of days. I replaced the tube and have the old one
>> off the bike. Tires are kevlar belted and there does not seem to be an
>> obvious leak in the tube. I have dunked the tube in water already.


> And try wiggling the valve stem. Sometimes a tiny crack near the valve
> stem won't show up with low pressure until you help it a little by
> tipping the valve to one side.


Don't forget to check the end of the valve that is farthest from the
tube. You wouldn't be the first to have a leaky stem.

--
Dave
dvt at psu dot edu

Everyone confesses that exertion which brings out all the powers of body
and mind is the best thing for us; but most people do all they can to
get rid of it, and as a general rule nobody does much more than
circumstances drive them to do. -Harriet Beecher Stowe, abolitionist and
novelist (1811-1896)
 
B

Bill Sornson

Guest
Michael Warner wrote:
> On Wed, 06 Sep 2006 14:15:13 -0500, catzz66 wrote:
>
>> Are there any tricks to finding a pesky tube leak? Tire goes
>> completely flat over a period of days. I replaced the tube and have
>> the old one off the bike. Tires are kevlar belted and there does
>> not seem to be an obvious leak in the tube. I have dunked the tube
>> in water already.

>
> Pump the tube up to twice its flaccid width - that makes the hole
> much bigger, and puts more air pressure behind it.


And when you hear the BOOM!!!!!!!!!!!, back it off a little.

<eg>
 
D

Donald Gillies

Guest
I have had good success with drowning the tube (with weights) in a lot
of water, brushing off all the tubes while underwater, and going for a
20 minute coffee break, then coming back and looking for a tiny bubble
somewhere on the outside of the tube.

If you've tried all the other good suggestions on this thread and
still cannot find the leak, then chances are good that it's a very
slow leak inside the valve, which cannot be fixed.

- Don Gillies
San Diego, CA
 
D

Donald Gillies

Guest
catzz66 <[email protected]> writes:

>Are there any tricks to finding a pesky tube leak?


Run your thumb very slowly along the INSIDE of the tire (not tube)
until you find a sharp piece of glass or metal that is protruding
INSIDE of the casing. Remove this sharp object and then, match up the
tire with the tube and look for a hole in the tube in the same place.
You do line up your tire labels with your valve stem when you mount a
tire don't you ?? I hope so, otherwise this technique cannot be
leveraged.

- Don Gillies
San Diego, CA
 
W

Werehatrack

Guest
On Wed, 06 Sep 2006 14:15:13 -0500, catzz66 <[email protected]>
wrote:

>Are there any tricks to finding a pesky tube leak? Tire goes completely
>flat over a period of days. I replaced the tube and have the old one
>off the bike. Tires are kevlar belted and there does not seem to be an
>obvious leak in the tube. I have dunked the tube in water already.


Some leaks don't become apparent until the tube is fairly well
distended. If you've been inflating it enough that the leak should be
showing up, then there's a good chance that it's in the valve or at
the base of the stem.

Wiggle the stem while holding that area under water. If the leak
makes itself known when the stem is deflected in a certain direction,
the leak is at the base of the stem. This is not uncommon. If there
are bubbles rising from the end of the valve, the problem is equally
obvious.

The other likely successful solution is to simply replace the $5 tube
with a new one. It's easily possible to spend a lot more time trying
to find a leak than it's worth.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.
 
M

Michael Press

Guest
In article <[email protected]>,
[email protected] (Donald Gillies) wrote:

> catzz66 <[email protected]> writes:
>
> >Are there any tricks to finding a pesky tube leak?

>
> Run your thumb very slowly along the INSIDE of the tire (not tube)
> until you find a sharp piece of glass or metal that is protruding
> INSIDE of the casing. Remove this sharp object and then, match up the
> tire with the tube and look for a hole in the tube in the same place.
> You do line up your tire labels with your valve stem when you mount a
> tire don't you ?? I hope so, otherwise this technique cannot be
> leveraged.


It can. I leave to chance the orientation of the tube,
then match the tube to the tire both ways, if necessary,
to find the hole in the tube.

--
Michael Press
 
M

Michael Press

Guest
In article <[email protected]>,
Werehatrack <[email protected]> wrote:

> On Wed, 06 Sep 2006 14:15:13 -0500, catzz66 <[email protected]>
> wrote:
>
> >Are there any tricks to finding a pesky tube leak? Tire goes completely
> >flat over a period of days. I replaced the tube and have the old one
> >off the bike. Tires are kevlar belted and there does not seem to be an
> >obvious leak in the tube. I have dunked the tube in water already.

>
> Some leaks don't become apparent until the tube is fairly well
> distended. If you've been inflating it enough that the leak should be
> showing up, then there's a good chance that it's in the valve or at
> the base of the stem.
>
> Wiggle the stem while holding that area under water. If the leak
> makes itself known when the stem is deflected in a certain direction,
> the leak is at the base of the stem. This is not uncommon. If there
> are bubbles rising from the end of the valve, the problem is equally
> obvious.
>
> The other likely successful solution is to simply replace the $5 tube
> with a new one. It's easily possible to spend a lot more time trying
> to find a leak than it's worth.


Learning to find a leak quickly is worth the time spent.

--
Michael Press
 
M

Michael Warner

Guest
On Wed, 06 Sep 2006 22:26:27 GMT, Bill Sornson wrote:

> And when you hear the BOOM!!!!!!!!!!!, back it off a little.


LOL. That hasn't happened to me, but I think it'd be a satisfying
end to an annoying tube :)

--
Home page: http://members.westnet.com.au/mvw
 
catzz66 wrote:
> Are there any tricks to finding a pesky tube leak? Tire goes completely
> flat over a period of days. I replaced the tube and have the old one
> off the bike. Tires are kevlar belted and there does not seem to be an
> obvious leak in the tube. I have dunked the tube in water already.If you listened and tried everything everyone has told you and you still don't have any luck finding the leak. Just go out and buy a few replacement tube and trash that one.