Author Topic: Tyre Valve Failures  (Read 5099 times)

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Offline iNCORRIGIBLE

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Tyre Valve Failures
on: 17 September, 2021, 07:54:14 PM
Hi All. Have had two rapid tyre deflations in the last 18 months. Brass core with valve mechanism & cap  complete all depart the rubber valve body  under tyre pressure...not very pleasant! Any thoughts please. p,s. can tyre sealants be involved? Thanks.Ed. :005:
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Offline Art

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Re: Tyre Valve Failures
Reply #1 on: 18 September, 2021, 12:17:34 AM
Not sure I'm understanding what you're saying but if the tyre valve has failed it should be replaced.

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Offline iNCORRIGIBLE

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Re: Tyre Valve Failures
Reply #2 on: 18 September, 2021, 09:32:23 AM
Hi ,Art.One of a number of causes i am pursuing is whether or not the tyre puncture sealant I use has had some unfavourable effect on the effectiveness of the seal between the Schrader valve brass inner body and the rubber main body which is pulled into the wheel rim on installation. On two occasions now the brass inner complete with the  Schrader inner has been ejected from the main rubber containment /body of the valve resulting in rapid deflation. All thoughts gratefully sought please. Ed.
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Offline Art

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Re: Tyre Valve Failures
Reply #3 on: 18 September, 2021, 12:09:06 PM
There should be be barbs holding the valve body in the rubber sleeve, that's sounding more like a faulty batch of valves to me. After each failing were the valves replaced from the same suppliers stock?

edit: Of course there are valve stems of varying qualities, some are of very dubious quality.
Last Edit: 18 September, 2021, 12:21:13 PM by Art

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Offline Shed

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Re: Tyre Valve Failures
Reply #4 on: 18 September, 2021, 04:38:27 PM
Tyre puncture sealant, is exactly that. It's to seal a puncture so you can get yourself to a garage for a proper repair. Whether you want to ride around with the stuff inside in the hope of it being a preventative all the time is your business, but for me, it's a definite no.

The sealant stuff you put in can clog the valves, and if you/whoever originally put this stuff in with the wheel downwards, i.e. with the valve at 6'oclock, you'll have coated the valve stem threads with the sealant too, thereby now preventing the valve core from tightening up properly. (There is also the possibility the threads are simply knackered too). Or the entire stem/schrader is fubar.

Anyway, put your wheel at 12'oclock position or near enough. Using a valve core removal tool, err, remove the core. Wash it in warm/hottish water to remove the gloop. Also, use the water with a cotton bud (the ones you stuff in your ear, but shouldn't), or suitably sized implement wrapped in cloth, to clean out the valve stem body and the threads in there. Replace the valve core into the stem, tighten up. Inflate. Job done.

Then, get to a bike tyre garage and have it checked properly.

You don't specify where this 'blow-out' has happened (twice!)? - hopefully when it's just sat on your driveway. So I'd be taking the wheel in loose, no way would I be riding it.

Last Edit: 18 September, 2021, 04:56:22 PM by Shed

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Offline iNCORRIGIBLE

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Re: Tyre Valve Failures
Reply #5 on: 18 September, 2021, 04:58:48 PM
*Originally Posted by Art [+]
There should be be barbs holding the valve body in the rubber sleeve, that's sounding more like a faulty batch of valves to me. After each failing were the valves replaced from the same suppliers stock?

edit: Of course there are valve stems of varying qualities, some are of very dubious quality.

Hi again,Art. No visible barbs or any other machining on the smooth brass bodies which might have ensured a reliable bonding with its rubber housing. Tending to your view of a faulty batch No way at present of knowing source of supplier. Thanks.Ed.
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Offline Shed

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Re: Tyre Valve Failures
Reply #6 on: 18 September, 2021, 05:07:49 PM
*Originally Posted by iNCORRIGIBLE [+]
No visible barbs or any other machining on the smooth brass bodies


Schrader valves do not have 'smooth brass bodies', nor do they have 'barbs'. They have a threaded inner stem to which the valve core (which is also threaded), tightens up to.
What are you looking at?  :027:

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Offline iNCORRIGIBLE

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Re: Tyre Valve Failures
Reply #7 on: 18 September, 2021, 05:10:50 PM
Hi Shed.Thanks for your swift input.Both incidents happened in the garage whilst checking pressures & about 18 months apart.The brass body & its internals, including the valve cap, all left on the same bus :005: Tending to the idea of a faulty manufacture.Ed.
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Offline Shed

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Re: Tyre Valve Failures
Reply #8 on: 18 September, 2021, 05:14:56 PM
*Originally Posted by iNCORRIGIBLE [+]
Hi Shed.Thanks for your swift input.Both incidents happened in the garage whilst checking pressures & about 18 months apart.The brass body & its internals, including the valve cap, all left on the same bus :005: Tending to the idea of a faulty manufacture.Ed.

Assuming you read my first post? You need to take the wheel to a bike tyre garage, so someone who deals with bike tyres & wheels can advise you accordingly.
Is the valve stem you have on a bike one, or a car one? Not that it matters now, you still need it replaced.:028:
Last Edit: 18 September, 2021, 05:19:04 PM by Shed

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Offline iNCORRIGIBLE

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Re: Tyre Valve Failures
Reply #9 on: 18 September, 2021, 05:39:36 PM
Hi again, Shed.I am focussing ,presently, on how the brass valve body, complete with its internals is contained within its overall rubber sleeve upon manufacture. It appears it is bonded ,hermetically, and it is at this point where the failures have occurred. I will be approaching the appropriate manufacturers advising them of the obvious concerns.Ed.



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