Where does this fit

Post by **SvMinor** » Wed Dec 23, 2009 10:25 am

I fitted the water temp sensor and took out the thermostat there is plent of room for the sensor.the only thing is the retaining nut that holds the sensor in place tightens up til halfway up the threads.I suppose this is because of the shoulder part of the sensor taking up space in the apeture.

I checked out a mini parts supplier online and found the adapter.but I dont think it would make any difference.because the sensor can only go into the apeture as far as the shoulder

Post by **PSL184** » Wed Dec 23, 2009 10:34 am

Mark=1960=2=door=saloon wrote:I fitted the water temp sensor and took out the thermostat

but you need the thermostat fitted !!

Post by **mike.perry** » Wed Dec 23, 2009 1:31 pm

It is indeed a male -female adapter

I beg to disagree but I have just checked my Traveller and the temp gauge sensor has an adaptor with a male thread on one end which screws into the cylinder head, a central collar with a spanner hex and a male thread on the other end onto which screws the large nut which secures the sensor

Post by **bmcecosse** » Wed Dec 23, 2009 6:06 pm

Aye -but the one show here, clearly has a MALE thread - and so needs a female thread on the adapter to mate with! Other designs can obviously be different. The reason your 'nut' won't screw right up - is because the bulb has bottomed out - I'm surprised the thermostat has anything to do with it! The adapter pulls it back - and allows it to seat properly.

Post by **mike.perry** » Wed Dec 23, 2009 8:40 pm

Looks like Iam going to have to post a photo tomorrow.

Post by **bmcecosse** » Wed Dec 23, 2009 9:36 pm

No - I (we?) quite believe you - but this one needs a female fitting!

Post by **SvMinor** » Wed Dec 23, 2009 11:46 pm

I took out the thermostat to see if there was room for the temp sensor!
I know you need the thermostat fitted IM NOT THAT STUPID!!

The reason I removed the thermostat is because the Mini Man showed me a mini head and fitted the sensor to it and it was touching the inside of the head,so the nut would not even thread into the apeture,if it was forced it would have bent the sensor.there is far more space inside my 1098 head,I dont know what the mini one was.

I have the gauge fitted and there are NO leaks and the gauge is working fine.

Post by **bmcecosse** » Thu Dec 24, 2009 9:25 am

Great success!

Post by **autolycus** » Thu Dec 24, 2009 1:12 pm

I wonder whether the adapter has two purposes: as a spacer, for those engines which need one; and to provide a more precisely machined seating for the brass(?) sleeve on the bulb on the end of the capillary. Even if the hole in the head had been machined accurately 50 years ago, it's possible that exposure to coolant for that time, especially if a gauge has never previously been fitted, has eroded the mating surface. You'd then be relying on parallel threads to seal, which sometimes works, as Marketc has shown, but is perhaps less reliable than a copper washer between a spot-surfaced face on the head and the adapter.

But I'm glad it worked for him.

Now to dig out some old Practical Motorist articless on repairing and refilling temperature gauges - they're getting too dear to throw away.

Kevin

Post by **bmcecosse** » Thu Dec 24, 2009 1:54 pm

Yes - mine certainly needs the machined face for the bulb. I don't think you can sensibly 'refill' them at home - I believe the liquid is ether ?

Post by **IslipMinor** » Sun Dec 27, 2009 10:22 am

There are two types of end fitting on Smiths capillary gauges. The 'male' version that Mark has, which needs a female/male adaptor to ensure that the bulb is in the right place and provides a 'proper' mechanical seal for it as well. The head is tapped 5/8" UNF and the adaptor has 2 x 5/8" UNF threads, one male and one female, which as Kevin says, screws into the head using a copper washer as a seal. The taper seat in the adaptor seals the bulb - PTFE tape and/or sealant defintiely not required!

Without the adaptor the bulb will bottom out on the head casting, which it not designed to do, and there is no proper sealing.

The second type has a female nut for the end fitting, which is 3/8" BSP parallel, and requires a double ended male adaptor, one end 5/8" UNF to go into the head, and the other 3/8" BSPP to accept the bulb end fitting. The sealing is again a copper washer between the adaptor and the head, and this time a copper ring that fits over the end of the bulb and seals it to the adaptor - again no PTFE or sealant.

Mark, I would get an adaptor, the 5/8" UNF male/female type and refit the bulb using that to make sure that no damage is done to the bulb and the sealing is reliable.