Tyre Valves

[tonyfletcher]

Hi ,

 

Having just returned today from spending last week touring from Trier to Koblenz I would like any comments on Tyre Valve problems you have may encounted.

 

For the second time this year and on 2 different tyres the Valves have failed. Luckily on both ocassions we were stationary.

 

Do MotorHomes have to have special valves fitted?. My tyre pressures do not seem to be excessive at 65 psi?

 

I welcome any comments

 

PS Didn't spoil a great Holiday

Wifes PS - If the Gent from Sweden who helped me with changing the Wheel is a memeber of MMM forum and is reading this 'Thanks Again and enjoy the rest of your Holiday.

 

Tony

[colin]

Give us a clue, what base vehicle is it!

My guess would be transit as there have been previous posts re tyre valves on them.

[tonyfletcher]

Hi,

 

Sorry It's a Ducato 2.8JTD on 03 Plate

 

Cheers

 

Tony

[mirage]

Are your tyre valves of the rubber type, mine were and on the second deflation of the front wheels due to valve failure (over two years) on the drive I did some research only to find that only steel valves should be used with tyres in excess of 50psi. I had all mine renewed I think they only charged £10 per wheel. I was so pleased to have got "away" with it I could`nt be bothered arguing with the dealer, though did raise the safety issue. There was a Swift recall on the subject if I remember correctly.

[Derek Uzzell]

The vast majority of motorhomes use either 'snap-in' or 'clamp-in' tyre valves.

 

A snap-in valve has a flexible rubber body with a metal 'tube' going through its centre. It is physically levered into the wheel-rim and the shape and flexibility of the rubber body permits the valve to 'snap' into the rim's valve-hole, forming an air-tight seal against the rim. There are numerous variations of snap-in valve but, basically, they can be split into valves designed to cope with inflation pressures no greater than about 65psi (let's call these 'car' valves) and valves designed to handle at least 100psi (let's call these 'high pressure (HP)' snap-in valves).

 

A clamp-in valve is quite different, being made of metal and completely rigid. Air-tightness is achieved by a circular rubber seal on the valve's base being clamped against the inside of the wheel-rim at the valve-hole position by means of an external nut that is threaded on to the valve's stem. Clamp-in valves are designed to handle inflation pressures well beyond the capability of snap-in valves and, historically, have been employed on motorhomes fitted with Fiat's Camping-Car Pack that included Michelin "XC Camping" tyres with a design-maximum inflation pressure of 80psi. (I can't remember what the Swift recall was about, but I suspect it may have involved 'car' snap-in valves being used on alloy wheels fitted with 80psi-capable camping-car tyres.)

 

Tony:

 

A 65psi inflation pressure is right at the design-ceiling of a 'car' snap-in tyre valve, and it would be preferable for a motorhome using 65psi in its tyres that HP snap-in or clamp-in valves be employed.

 

Last year, having had the factory-fitted HP snap-in valves rupture (in quick succession) on both rear wheels of my Transit-based Hobby and at an inflation pressure of 55psi, I had all five valves changed to the clamp-in type. In principle the German-made HP valves chosen by Ford should have been well up to the task and shouldn't have failed, but practice proved otherwise. As Colin suggests, there is speculation that Mk 6 Transits fitted with original-equipment HP snap-in tyre-valves have suffered an unusually high number of valve failures, though the root cause remains inconclusive.

 

I've looked through all your earlier postings, but I can find no indication of exactly what make/model of motorhome you own. As far as I'm aware Ducato-based motorhomes have never used HP snap-in valves, just 'car' snap-in valves or clamp-in valves. As the chances of a clamp-in valve suddenly failing are low, it's likely it's got 'car' snap-in valves, which suggests normal light-goods-vehicle tyres (rather than specialised camping-car ones), which, in turn, suggests a panel-van conversion (or possibly a compact, light coachbuilt model).

 

Whatever the case, having now had two valve failures, you need to consider seriously whether you should replace the non-failed valves as a precautionary measure. Should you choose to do this (and assuming your vehicle has 'car' valves), it might be preferable to go the whole hog and do as Mirage and I have done and have all five existing valves replaced with the heavier-duty clamp-in type.

 

(I hesitate to say this, but, although there's a sporting chance of getting informed advice from the UK tyre trade on suitable tyres for motorhomes, or even on suitable inflation pressures, there's much less likelihood of obtaining expert information about tyre-valves.)

[cronkle]

I think I would get the other valves changed as well :-( unless, of course, you know that they have been change more recently than the others.

[colin]

Reminder to the newer members, if you add MH make/model to your 'location' it can make things easier for those trying to advise you, sometimes it may not seem relavant for a particular problem, but sometimes it is if a certain make/model has had a faulty batch of components.