Tyres - tyre valves

- by Ed Loader

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My Austin 7 Ruby is still fitted with the original type Natural India rubber inner tubes. These give a long and trouble free service. But there is one slight problem which is common to all the inner tubes of this construction, namely that India rubber is very slightly porous, this, of course, necessitates regular attention to the tyres’ air pressure. But with my Ruby, there was one wheel that seemed to always be requiring attention due to a loss in air pressure. I checked for a slow puncture in the inner tube but found no air leak. Next, l changed the valve several times which made no difference to the air loss.

After each change of valve, I carried out the age old test of using spittle on your finger tip to test for a faulty valve, but this showed no discernible air leak, so now I had to put my thinking cap on.

Then I suddenly remembered something which I learnt from my army days in the REME. We were taught never to use spittle on suspect leaking valves, instead use a small amount of washing up liquid. So I tried this tip on my suspect inner tube valve. The result was after approx 30 seconds a tiny air bubble started to form, so success at last, but the next problem was curing the minute leak, remembering, of course, the valve insert had already been changed several times. So in my jar of spare valves was a four legged tool as per the enclosed photo. On examining this tool, I worked out the individual function of each leg.

These were :
1. a die to restore the external valve threads.
2. a key to change valve inserts.
3. a tap to restore the valve internal threads.
4. a tool to extract broken valve inserts.

So using the tap, the internal threads were restored and a new valve insert fitted. On testing afterwards the results were 100%successful, meaning that the offending tyre pressure could now be checked monthly instead of weekly. So next question, where can this tool be purchased? I have seen them for sale in Halfords and I am sure motor accessory outlets would also stock them. This tool is compact and lightweight, so can easily be part of your vehicle’s tool kit and I can highly recommend its purchase.

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PS I can now recollect the REME version. It was contained in a large metal box in which were the required tap and die and their holders, together with other tools required to recondition valves.
This tool set was not part of the vehicles standard equipment. It had be withdrawn from the tool stores using a requisition in triplicate!


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