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Capillary temperature gauge


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I’m getting seriously pithed off at having to have my capillary gauge re-soldered where it vibrates to pieces at the  bulb, albeit every 10 years or so. A skill I do not possess and I haven’t yet found somebody here in France capable of doing it.

At well over £100 being asked nowadaysby UK suppliers (does anybody know otherwise?) the difficulty is compounded by the hassle of Brexit associated difficulties if I send it to the UK. So I’m thinking of going electric as I’ve found a sender and reasonably period looking gauge in my box of treasures.

Has anybody gone down this route?

james

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13 minutes ago, james christie said:

I’m getting seriously pithed off at having to have my capillary gauge re-soldered where it vibrates to pieces at the  bulb, albeit every 10 years or so. A skill I do not possess and I haven’t yet found somebody here in France capable of doing it.

At well over £100 being asked nowadaysby UK suppliers (does anybody know otherwise?) the difficulty is compounded by the hassle of Brexit associated difficulties if I send it to the UK. So I’m thinking of going electric as I’ve found a sender and reasonably period looking gauge in my box of treasures.

Has anybody gone down this route?

james

Ive had a few that have gone down this route  but you must have the capillary wrongly fitted to have this happen so often as Ive had cars that were still running their original ones. Is it sufficently clipped to the fuel pipe alongside the engine and then a small curve out and then into its fitting. also a couple of turns at the rear of the engine before it goes into the bulkhead?

Stuart.

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30 minutes ago, james christie said:

I’m getting seriously pithed off at having to have my capillary gauge re-soldered where it vibrates to pieces at the  bulb, albeit every 10 years or so. A skill I do not possess and I haven’t yet found somebody here in France capable of doing it.

At well over £100 being asked nowadaysby UK suppliers (does anybody know otherwise?) the difficulty is compounded by the hassle of Brexit associated difficulties if I send it to the UK. So I’m thinking of going electric as I’ve found a sender and reasonably period looking gauge in my box of treasures.

Has anybody gone down this route?

james

Yes brother has it on his TR2.  Used a TR4 gauge, sender and voltage stabiliser.   Add a similar temp sender in the oil system and a change over switch at the dash, so you can frighten yourself with oil temp. shewn on the same but shared gauge.

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On 12/4/2021 at 11:25 AM, james christie said:

I’m getting seriously pithed off at having to have my capillary gauge re-soldered where it vibrates to pieces at the  bulb, albeit every 10 years or so. A skill I do not possess and I haven’t yet found somebody here in France capable of doing it.

At well over £100 being asked nowadaysby UK suppliers (does anybody know otherwise?) the difficulty is compounded by the hassle of Brexit associated difficulties if I send it to the UK. So I’m thinking of going electric as I’ve found a sender and reasonably period looking gauge in my box of treasures.

Has anybody gone down this route?

james

Hi James

mine has just broken after some seriously rough roads on parts of the Pyrenees Rally, mind you that’s the first time in 41 yrs. I’ve sent it to Speedograph Richfield and await its return. It was installed correctly but as with yours fractured by the bulb. It should be back this week and I’ll report on its performance.

Iain

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The only problem I've had is getting the bulb out of the housing after 50++ years. They tend to get stuck and I tend to get impatient and break the capillary seal.

I agree the electric makes the dash removal simpler but how often do you need to remove it?

Tom

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My capillary temp gauge packed up last week.

There is a fellow here in Sydney who does them so I gave him a call. He asked when it was last done, very early 1980s I said at a place called Olympic Instruments. He said he was at Olympic Instruments back then so would have done it.

I asked if he provided a warranty as his last job can't have been too good, it only lasted nearly 40 years.

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  • 2 weeks later...

There was an article in TRaction about capillary gauges in 2000;   Issue 162 - Apr-May 2000, Page 25

You can see it by searching in the Index: https://www.tr-register.co.uk/tr-action-index

John

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Calibration is not easy to do Adrian, because it really requires the gauge, complete with all its tubing, to be removed from the car with the almost certainty of breaking the tube somewhere; though It might be possible to do something if you can pull the gauge forward out of the dash far enough to allow the bezel and glass to be removed. If the error is all the way up the range, adjustment may be as simple as tweaking the pointer a bit.   I can't find any pictures of the insides of a Smiths gauge but the pointer is usually driven by a quadrant gear mechanism and it could be that yours has somehow jumped a tooth. I can't think of any other way it could be reading high. 

For calibration some sources speak of  bending the linkage that connects the coiled bourdon tube to the pointer gear mechanism (never bend the tube itself) but that would require the gauge face to be removed. Easy on the bench but not so easy in-situ. Everything is delicate so you would have to be very careful.  If you crack the tubing the di-ethylether escapes and then you are in trouble.  

 

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I calibrated mine before fitting to the car. Adjustment was simply by bending the needle to point at the correct temperature (which I set using hot water in a jug with a digital gauge) I set it to be correct at 185°F.

Bob

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3 hours ago, Adrian Fuller said:

Hi my capillary temp gauge on my 3a is reading about 20 deg F too high,

Adrian.

I think that the easiest solution is to mentally subtract 20 from whatever reading you see.

Any other method is almost certainly going to end in disaster.

(That last thing you want just before Christmas is a load of escaped  di-ethylether running around the garage.)

 

Charlie.

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Diethyl ether is good old anaesthetic ether, which is flammable and explosive in the right air-vapour mixture.   The vapour is heavier than air and will get into places such as inspection pits, so yes, you don't want to have it loose in your garage.

But the volume of ether in the capillary system must be very small!   Ether is large part of the many "Start ya barsteward" sprays.   TRiumph owners would never admit to having any of that in their garage, would they, but maybe you have seen it used, by owners of lesser cars?       Used in moderation it's not that dangerous, and each spray may contain as much as a capillary gauge does!

John

PS Yes, I have given ether anaesthesia, twice in my life!

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  • 2 weeks later...
2 hours ago, ctC57212 said:

On mt TR3a it's stuck in the housing. Any tips how to get it out in one piece?

 

regards Bob

As Bob says, lots of diesel. If you can remove the housing carefully without damaging the capillary. Then with some plasticine make a reservoir into which you can poor the diesel and let it soak it’s way through the crud. It took three days for the diesel to appear on the outer surface, but once it had removal was straight forward. Now it’s regularly removed for an application of copperslip:-)

Iain

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1 minute ago, iain said:

If you can remove the housing carefully without damaging the capillary.

Be very careful if you do this. Take all the clips off so the tube is free as possible and do not bend the capillary tube sharply as you move the housing  - particularly nearest to the bulb where it is most vulnerable.  

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41 minutes ago, RobH said:

Be very careful if you do this. Take all the clips off so the tube is free as possible and do not bend the capillary tube sharply as you move the housing  - particularly nearest to the bulb where it is most vulnerable.  

Agreed.

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