Corky 8 Posted February 27, 2010 Share Posted February 27, 2010 Hi,today I noticed two of the tryes on my motorhome were showing sign,s of deflation,a scan around the tyre revealed no penetration of any foreign bodies,on checking the tyre valves with soapy water it showed a mass of bubbles around the metal valve stems ,tightening them up to fully tight did not stop or lessen the air escaping,I then released the nutted stem completly and took it off ,the air presure in the tyre keeping the valve body from falling in/out, I moved the valve body around attempting to re seal it I then refitted the nutted stem and tightened it up in small half turns to see if I could find the correct sealing preasure,after an hour of this I only managed to seal it to a tiny air leak ,an air leak none the less, has anyone else had this problem and solved it ? (search not working ) Thanks in advance, Link to comment Share on other sites More sharing options...
Derek Uzzell Posted February 28, 2010 Share Posted February 28, 2010 The tightening torque for metal clamp-in valves is normally quite low - about 2 or 3 lb/ft and, if they are over-tightened, it can damage the rubber seal. If your valves are leaking at the (presumably steel) wheel rim, there's only one sure cure and that's to remove the valves from the rim and either replace the rubber seal on the valve's base or replace the complete valve assembly. It could be there's corrosion where the valve stem passes through the wheel rim or, probably more likely, you've just got some duff valves. As two valves are leaking, I suggest you do them all rather than risk the ones that are still OK failing in the near future. (I notice there was a VOSA 2007 Ducato tyre-valve-related recall, but I doubt that has any bearing on your problem.) Link to comment Share on other sites More sharing options...
Corky 8 Posted February 28, 2010 Author Share Posted February 28, 2010 Thank you Derek, my wheels are alloy,and I understand it wouldnt be much presure required to seal the valve seat that,s what I was aiming for when I tightened them slowly,but as you say I think its a visit to are Tyre service centre for a cure ,Much obliged for you time Derek , Dennis Link to comment Share on other sites More sharing options...
747 Posted February 28, 2010 Share Posted February 28, 2010 If you can source a supplier for metal tyre valves then please post it on here. The reason I am asking is because I could not get a metal valve from any of the big companies who deal in tyres, ie National Tyres, Kwikfit etc. I wanted to carry a spare wheel, got the rim, got the tyre arranged but had the devil of a job sourcing the valve. I finished up with one from a small firm in the North East just because the tyre fitter had a one in his toolbox. Link to comment Share on other sites More sharing options...
Basil Posted February 28, 2010 Share Posted February 28, 2010 747 - 2010-02-28 12:47 PM If you can source a supplier for metal tyre valves then please post it on here. Available here £30 for 4, second section down http://www.tyresave.co.uk/alloyvan.html Bas Link to comment Share on other sites More sharing options...
747 Posted February 28, 2010 Share Posted February 28, 2010 Well done Basil, Thanks. Link to comment Share on other sites More sharing options...
Keithl Posted February 28, 2010 Share Posted February 28, 2010 Hi Corky, The problem with metal valves in alloy wheels is usally corrosion due to dissimilar metals, the steel valve causes the alloy wheel to corrode around the seating face. Get your local tyre dealer to break the bead and let you have a look at what is happening inside. I personally wouldn't recommend using rubber valves in place of metal if the fitter should suggest that as a fix, they can't stand the pressure! Keith. Link to comment Share on other sites More sharing options...
Basil Posted February 28, 2010 Share Posted February 28, 2010 If you check out the valves at the link in my previous post they are designed especially for use with alloys and are plated and have nylon isolation barriers fitted. Bas Link to comment Share on other sites More sharing options...
lennyhb Posted February 28, 2010 Share Posted February 28, 2010 Keithl - 2010-02-28 2:52 PM Hi Corky, The problem with metal valves in alloy wheels is usally corrosion due to dissimilar metals, the steel valve causes the alloy wheel to corrode around the seating face. Get your local tyre dealer to break the bead and let you have a look at what is happening inside. I personally wouldn't recommend using rubber valves in place of metal if the fitter should suggest that as a fix, they can't stand the pressure! Keith. There are high pressure rubber valves available they have a brass insert I have them on my van. Most tyre places don't stock them you need to go to a commercial tyre dept. Link to comment Share on other sites More sharing options...
Corky 8 Posted February 28, 2010 Author Share Posted February 28, 2010 Many thanks for your response,s, My Motorhome is only 14 month old so I will refer things to the dealer,no doubt they will come under consumables, I too bought a spare Burstner alloy wheel also bought a tyre online and was lucky enough for my local tyre company Mc Conechy to fit the tyre and steel/brass tyre valve for £5:00, it the first time I have had any trouble with tyre valves in over fifty odd years of all kinds of vehicles, but theres a first time for everything as they say, once again thank you for your replies, Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 1, 2010 Share Posted March 1, 2010 As far as I'm aware metal 'clamp-in' valves are always made from brass (and normally nickel-plated) rather than steel. When two of the standard high-pressure 'rubber' valves failed on my Transit, I replaced them with clamp-in valves from http://www.auto4.co.uk It perhaps needs adding that, if you are planning to source the tyre-valves yourself (and you may well have to do this), there are differences in design and you could find that your local tyre supplier (or even the supplier of the valves themselves) may not be able to offer advice about which particular valve will be most suitable. The Alligator-made valves I was planning to use came in two formats and both had the nylon 'washer' mentioned by Basil. The sole difference was that one valve format had a metal washer above the nylon one, while the other valve didn't. I chose the valve with the extra metal washer (as it seemed to make sense to have it), but I don't know what relevance that washer has and neither did the Auto4 specialist I discussed the matter with. Anyone with a motorhome based on a Transit Mk 6 may find it worthwhile looking at the following valve-related earlier thread. http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=4963&posts=27 Link to comment Share on other sites More sharing options...
Brian Kirby Posted March 1, 2010 Share Posted March 1, 2010 Derek Uzzell - 2010-03-01 9:36 AM As far as I'm aware metal 'clamp-in' valves are always made from brass (and normally nickel-plated) rather than steel. .......... However, if the nickel plating is damaged the brass will be in contact with the aly. Since brass contains copper, and copper and aluminium are at opposite ends of the electrochemical series of metals, the inevitable result will be copper 1: aly nil! It is not a happy combination! Exposure to winter road salt will accelerate the reaction. If a stainless steel valve is available, it will be the only safe clamp in option, otherwise, switching to high pressure snap in valves may be the best solution - so long as you don't use tyre pressures exceeding about 4.5 bar (but check actual valve for max pressure recommendations). Link to comment Share on other sites More sharing options...
lennyhb Posted March 1, 2010 Share Posted March 1, 2010 Brian Kirby - 2010-03-01 12:35 PMDerek Uzzell - 2010-03-01 9:36 AM As far as I'm aware metal 'clamp-in' valves are always made from brass (and normally nickel-plated) rather than steel. .......... However, if the nickel plating is damaged the brass will be in contact with the aly. Since brass contains copper, and copper and aluminium are at opposite ends of the electrochemical series of metals, the inevitable result will be copper 1: aly nil! It is not a happy combination! Exposure to winter road salt will accelerate the reaction. If a stainless steel valve is available, it will be the only safe clamp in option, otherwise, switching to high pressure snap in valves may be the best solution - so long as you don't use tyre pressures exceeding about 4.5 bar (but check actual valve for max pressure recommendations).Aluminium & Stainless are not compatible either, the aluminium will corrode when in contact with stainless steel.The snap in rubber valves are available in a high pressure version they have a brass insert. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted March 1, 2010 Share Posted March 1, 2010 If I remember correctly HP snap-in valves should be good for at least 100psi (and some ruggedised versions well above that), while metal clamp-in valves can handle up to 200psi. All snap-in tyre valves have a brass centre-stem - it's just that the stem's normally part-exposed on the HP versions. Having said that, I've seen non-HP snap-in valves with part-exposed brass stems. Link to comment Share on other sites More sharing options...
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