Persistant Punture.

[Andrew T]

I've had the same tyre back to repairers four times. He is adament that the leak is from the valve. So far it's has the valve reseated and glued in, a new valve fitted (and then reseated and glued in) a now a new metal valve fitted. It still leaks just not quite as fast.

 

I wondered if an innertube could be fitted (should they really be used on tubeless tyres ?) but was told they are not available for low profile tyres.

 

Do I recall once hearing that Alloys wheels can go porous with age ? Can anyone help ?

[Ivor_E_Tower]

Alloys often go porous with age. You can fit a tube to a tubeless tyre but it is not recommended (and I am not sure if it is legal). If the valve has been replaced, presumably the tyre has been re-seated on the rim so chances are that there is a good seal. Beginning to sound like you have a porous alloy; how fast does it loose air?

[Andrew T]

It's losing around 2-3 PSI/Day.

[chromedome]

Pour some water around the rim of the tyre, where it seats on the rim to make sure the bead of the tyre has sealed correctly. Check inner and outer rim.

 

You could also pour water around the valve.

 

Any signs of bubbles indicates a leak.

 

Sometimes after a puncture the bead or rim of the tyre gets damaged and doesn't seal properly.

 

Hope this helps.

[Masked Marauder]

I had the same problem when I had new rubber fitted to an Audi, one wheel was seeping out air and repeated attempts to seal the leak from the base of the valve failed.

 

In the end I got so pissed off with it that I put in a can of instant spare and it ceased to be an issue there and then, it was fine even when the tyre was changed a couple of years later.

 

 

 

 

 

.

[Andrew T]

Thanks all. I'll try a can of sealant and see if that does the trick. Obvious really I should have been able to think of that myself........

[Topbloke]

there are problems with the tyre not sealing on the bead this is what you should be looking at , there is a bead seal type of glue which we use at work that is painted around the rim where the tyre bead sits and if that dont work its a pourous rim, but i have never come across it before (but then i dont work in a tyre fit place) your tyre man should know about this glue as mentioned pry remove wheel from car, lay tyre flat and put water/ fairy liquid mix around where the tyre meets the rim , any bubbles and thats your problem

[seatkid]

Instead of using glue and chewing gum, why don't you just go to a good tyre depot and get it fixed properly :D

 

And how about using the spare?

[Ivor_E_Tower]

A "good" tyre place will take the tyre/wheel off and stick it in a water bath, pump it right up and look for the tell-tale sign of bubbles if the tyre is not seating correctly on the rim.

[Guest marcusheawood]

as an aside I believe that porous alloys can be repaired using a coating process on the rim.

 

Some racing cars use magnesium alloy wheels which are inherently porous, and their rims have a special coating in the well and bead area which makes them airtight.

[seatkid]

Some racing cars use magnesium alloy wheels which are inherently porous, and their rims have a special coating in the well and bead area which makes them airtight.

So do ordinary alloys, its called lacquer. A 4yr old factory alloy shouldnt "go porous".

Whats with this reseating/gluing malarky? Sounds like your ham fisted tyre fitter has damaged your wheel.

 

Go to a good tyre depot, Get it stripped down and inspect the rim/bead and valve seat thoroughly.

 

Always fit a brand new valve (some cowboys refit old valves - which always leak) of the correct length (short for alloys)

[Guest marcusheawood]

...very true seatkid, although laquer wasn't what I meant.

 

Andrew have you considered the possibility (however unlikely) that you have picked up a slow puncture which the fitter has not found; 2-3 psi per day would be tough to spot in a plain water bath.

[Andrew T]

I can't use the spare as it's a steel, also I always need a fully inflated spare to hand because of where we live and the number of punctures we get (at least 5 a year).

 

I've used the same tyre fitter dozens of times over the years and have confidence in him. I watched him inspect the seal at the bead and test it. I also saw the wheel in the water trough and confirmed that air is escaping at the base of the valve. If the goo seals it I'll be happy, if not I'll try another fitter.

[Andrew T]

3 days and not a PSI lost. Thanks MM for the Solution (excuse the crap pun).