Thats me lost

[Dangermouse]

Over the years I have had punctures just like every one else, but a non existant one is baffling me, my front tyre/tube deflates in about 6 hours from 115psi yet I have had the tube out and done all the normal tests to find out where the puncture is, felt it all around to see if I can feel the air coming out, didnt work so put my ear to it....nope then tounge........still mothing so I went down the old fashioned route with a sink full of water and went in 6" at a time and twisted n stretched the tube.......absolutely nothing, not one single bubble, did this for at least half an hr as the tube is an expensive 75mm valve lightweight one and I dont want to chuck it away, but theres absolutely no puncture BUT it goes down after a few hrs when in the tyre/on rim.........I am totally lost as I thought the valve must be leaking in the end but even thats not it.......help

 

[Gary E]

Did you leak check the valve itself? sometimes the core can leak.

 

[Dangermouse]

Yes Gary and will do it again as its flat again so out it comes..........AGAIN

 

[ColinJ]

Did you leak check the valve itself? sometimes the core can leak.

I am totally lost as I thought the valve must be leaking in the end but even thats not it.......help

Strange!

The only thing I can think of is that you didn't have the valve top screwed down tight when it was on the wheel so it leaked, but when you took the tube out and tested it, you tightened the valve properly.

 

[swee'pea99]

Baffling. It seems likely, tho', that there's a fault - probably in the valve - which only shows up at pressure - which is to say, pressure way above what you can produce with the thing out of the tyre. My guess would be, if you put it back on the rim, inflated it to 115, then stuck the wheel in a washing up bowl full of water, you'd see wee bubbles appearing out of the top of the valve. Slowly, but surely. However costly, I'm afraid it sounds like a gonner to me.

 

[ColinJ]

Or someone is teasing you and letting the air out when you're not watching!

 

[Gary E]

The problem with checking the tube outside of the tyre is that you can only inflate it a few psi otherwise it turns into a balloon animal.
Normally that's more than enough but try putting the tube in the tyre/wheel and pump up to full pressure. Then leak check the whole thing in the bath.
It won't tell you where the leaks coming from (unless it's the valve)
but at least it'll tell you you're not going mad

 

[PaulSecteur]

Try filling a bowl with water and add some washing up liquid to it.

Hopefully, when you remove the tube and observe it you should be able to see some tell tale bubbles on the surface.

 

[Gary E]

Swee'pea99 beat me to it, I must learn to type with more than 1 finger!

 

[MrJamie]

When ive had slow punctures, i've immersed the whole tube under water and left it for a bit then come back to see if teeny bubbles had formed anywhere. It'll be hard to find if it only lets air out above a high psi though.

 

[Gary E]

There comes a time with every tube when you just have to give up and pull the plug

 

[Dangermouse]

Its not defeating me......just put 80psi in, its well deformed but absolutely no leaks, with presta valve screwed down or loose, putting it back in the tyre to see.........yes with some fairy in the water, it simply isnt punctured and the valve is spot on......but I wont let it get the better of me

 

[Gary E]

You put 80 psi into an un-installed tube? Blimey I wouldn't have thought that was possible

Put your fingers in your ears just to be on the safe side

 

[Dangermouse]

Its not pretty, bulges all over but no leaks and it looks like its a front tube fron a penny farthing BUT its holding the air in.......

 

[Dangermouse]

AHA its down to 40psi but where the hell from