Kubota B1550 HST 4WD D850-5B engine thermometer sensor

[North Idaho Wolfman]

What is the sensor thread?

I have taken that plug and drilled it to fit a NPT fitting into it and used it as an adapter.

 

[North Idaho Wolfman]

3/8 X 24 tpi is a bolt thread, I've seen Kubota do this several times.
In all actuality, It's probably a British bolt thread or a Metric bolt thread.
Tough to cross over to anything else.

 

[Berry]

3/8 X 24 tpi is a bolt thread, I've seen Kubota do this several times.
In all actuality, It's probably a British bolt thread or a Metric bolt thread.
Tough to cross over to anything else.

This makes a lot of sense being a bolt thread. I think I will drill and tap. The sensor is 1/8 NPT, and there is enough meat for the threads. Thank you for the help once again

 

[Russell King]

3/8-24 threads per inch is fine thread bolt in the USA

Metric 10 mm is close to 3/8 and has 3 different pitches 1.5, 1.25 and 1.0

These can be confusing and easy to make mistakes between so just be sure you have the correct threaded part to fit the hole before you spend time modifying it for the sensor.

I am not sure how I would seal the straight threads but would probably use a sealing washer under a shoulder if there is room.

 

[N3BP]

I run a trio of Autometer gauges on one of my 7200's. For the water temp, I tapped a plug on the cylinder head near the front most injector. I did it a while ago, so I don't remember the exact size, but I believe it was a M16x1.5 or something close to that. It was definitely not a tapered thread though.
I teed off the oil pressure port in the block to a remote oil pressure sensor. If memory serves, the oil pressure port is a British taper. All the gauges are electrical and they've been working good for a few years now.

 

[Berry]

3/8-24 threads per inch is fine thread bolt in the USA

Metric 10 mm is close to 3/8 and has 3 different pitches 1.5, 1.25 and 1.0

These can be confusing and easy to make mistakes between so just be sure you have the correct threaded part to fit the hole before you spend time modifying it for the sensor.

I am not sure how I would seal the straight threads but would probably use a sealing washer under a shoulder if there is room.

Thank you Russell; I'm up in Canada and the thermostat housing for the B7200 (Canada) has a plug in it. I'm not sure why they put it in the tractors for Canadian models only as I'm sure we both have the same needs in different parts of the country temperature wise. Anyway this plug (straight thread) does seal with a crush washer. The plug is now discontinued by Kubota but there is aftermarket available. So in case I bugger this up I'm covered. I think I'm now committed to drill and tapping into the original plug for 1/8 NPT.

 

[Berry]

I run a trio of Autometer gauges on one of my 7200's. For the water temp, I tapped a plug on the cylinder head near the front most injector. I did it a while ago, so I don't remember the exact size, but I believe it was a M16x1.5 or something close to that. It was definitely not a tapered thread though.
I teed off the oil pressure port in the block to a remote oil pressure sensor. If memory serves, the oil pressure port is a British taper. All the gauges are electrical and they've been working good for a few years now.

Thank you for the input. I'll have to figure out how to share photos on this site.... I'm doing the same as you for the oil sensor except mine is electrical. As for the temperature sensor, I have a plug already in the thermostat housing that I am going to drill and tap for my sensor 1/8 NPT

 

[N3BP]

Thank you for the input. I'll have to figure out how to share photos on this site.... I'm doing the same as you for the oil sensor except mine is electrical. As for the temperature sensor, I have a plug already in the thermostat housing that I am going to drill and tap for my sensor 1/8 NPT

The oil pressure sensor I run is all electrical. You're limited with room everywhere on these small machines, so they make the most sense to use.
It is interesting to note that the CA models do have a port on the flange housing and the US models do not. Unfortunately the parts website doesn't specify its size.

 

[ChuckStone]

Thanks Wolfman and everyone in this thread. This helped me figure out how to install a temperature sensor in my Bobcat 553!