Water Temperature Sensor Thread - 1/8" NPT vs 1/8&q

jrslv · Oct 14, 2021

Hi all,

I need to change the water temperature gauge on my 1965 Ford 5000, which doesn't work. I'm not sure who's to blame - the sensor or the instrument cluster.

Instead I wanna install a digital one: https://www.trailtech.net/en-us/sho...mperature-black-probe-sensor-1-8th-x-28-bspp/

The problem is that this unit has the British thread [b:043e1a2706]1/8" 28 BSPP[/b:043e1a2706], whereas my tractor has [b:043e1a2706]1/8" NPT 27TPI[/b:043e1a2706]. The threads are close but not identical (as explained here: https://www.osmiowater.co.uk/bsp-npt-comparison). The American has 27 TPI vs 28 TPI of the British version, which also has the 55 angle vs 60 American.

Should I ignore the "subtleties" and just ram it in hoping that the teflon tape will make for the differences?

Thanks,
Jaroslav

This post was edited by jrslv on 10/14/2021 at 08:36 pm.

Sixty7camaro · Oct 15, 2021

I have the same issue with my '57 Workmaster. Tried two gauges listed to fit my tractor and had the same issue. I have not purchased one from YT yet. I did send
an email to YT inquiring about fitment of the gauge they offer and received no reply. I did save the old gauge but I really want a new one. I would advise you to
not force the fitting as you could end up with a bigger problem. If I remember correctly, the fitting seats the ferrule and seals the connection. Comparing my
original gauge to the new one I found that the fitting diameter to be the same but the thread pitch was slightly different. The new gauge is actually metric.

Bern · Oct 15, 2021

Pipe thread by its very design is interference thread. As close as those threads are, I'd ram it in and not think twice about it.

Hacke · Oct 15, 2021

(quoted from post at 06:32:43 10/15/21) Hi all,

I need to change the water temperature gauge on my 1965 Ford 5000, which doesn't work. I'm not sure who's to blame - the sensor or the instrument cluster.

Instead I wanna install a digital one: https://www.trailtech.net/en-us/sho...mperature-black-probe-sensor-1-8th-x-28-bspp/

The problem is that this unit has the British thread [b:39de767e93]1/8" 28 BSPP[/b:39de767e93], whereas my tractor has [b:39de767e93]1/8" NPT 27TPI[/b:39de767e93]. The threads are close but not identical (as explained here: https://www.osmiowater.co.uk/bsp-npt-comparison). The American has 27 TPI vs 28 TPI of the British version, which also has the 55 angle vs 60 American.

Should I ignore the "subtleties" and just ram it in hoping that the teflon tape will make for the differences?

Thanks,
Jaroslav

This post was edited by jrslv on 10/14/2021 at 08:36 pm.

Just to make sure:
"Surface TTO", but it has this probe for the coolant?:
https://www.trailtech.net/en-us/sho...sor-temperature-probe-sensor-1-8th-x-28-bspp/

BSPP is a cylindrical thread and NPT is tapered. They may work together when the male thread is NPT, but in this case you will have a cylindrical male thread trying to seal in a tapered female thread. I do not think that will work for you.

If it was me, I would drill and tap the foremost "blanking plate" on the intake manifold:
https://external-content.duckduckgo...RAAAOSwDnpdxtW0/s-l640.jpg&f=1&nofb=1

Or have one with the hose sensor.
Or get a set with the proper sender thread, should be NPTF actually.

RickB · Oct 16, 2021

Surely wouldn't be the first time that was done. I'd probably do it as well. Brass is also your friend.

Water Temperature Sensor Thread - 1/8" NPT vs 1/8&q

jrslv

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Sixty7camaro

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Bern

Well-known Member

Hacke

Member

RickB

Well-known Member

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