Farmall h welch plug/freeze plug

23afdahlbo · Oct 7, 2020

Hello, I'm getting some antifreeze in my
oil and I was wondering if the freeze plug
would be the culprit. It is a 1946 H, did
those have freeze plugs? The head was
machined and the gasket was replaced
multiple times so no issues there. Could I
replace the frost plug without taking the
engine out? I don't have any tools for
that... Thank you in advance

Al nickel · Oct 7, 2020

Are you thinking of a freeze plug on the engine block ??? I doubt that Farmall H s had those.

teddy52food · Oct 7, 2020

There is one in the front behind the timing gear cover.

SkipperII · Oct 7, 2020

I can think of no way that a welch plug would allow antifreeze into the crankcase.

Mike(NEOhio) · Oct 7, 2020

Look under the valve cover to see if there are any in the head. My Oliver had signs of water in the oil. It has seven brass welch (not freeze) plugs on the head and three are under the valve cover. The center one had a slight leak indicated by no sludge there. If you find one bad you should replace all of them.

John M · Oct 7, 2020

You retorque the head after it warmed up?

used red MN · Oct 7, 2020

Only the early years had the had the drive in plug behind the timing cover, sorry I don’t know what the year cut off was. Also if you don’t know the complete history of your tractor it could be possible an early engine was swapped into it. That would require checking the block casting code. Hopefully someone can chime in with the years that had them.

23afdahlbo · Oct 7, 2020

Do you know if I can access the plug without splitting the tractor or taking the engine out? Does anyone have any pictures of where it is located?

John M · Oct 7, 2020

Front end, and all that involves, has to come off. Crank pulley has to come off, timing cover and gears have to come off, governor has to come off just to get to the backing plate which this plug may or may not be. Again, did you retorque the headgasket after you ran it a bit?

23afdahlbo · Oct 7, 2020

The headgasket was replaced probably about 10 years ago by the previous owner who was having the same issue. I'd assume he retourqued it but I guess you should never assume...

John M · Oct 7, 2020

In that case I would replace the headgasket and go from there.

Dennis K (WA) · Oct 7, 2020

The engine and machine had matching s/n's if original on the H's.
Not sure when the plug was dropped from production.

I would first drop the pan before going further if you do not know the leak source. Add a little pressure to the cooling system, 10psi or so. Then look up from the bottom to see where the coolant is coming from. Clean cardboard under the engine may help also. Then decide what to do from there.
Good luck
Dennis

Farmall h welch plug/freeze plug

23afdahlbo

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Al nickel

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teddy52food

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SkipperII

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Mike(NEOhio)

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John M

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used red MN

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23afdahlbo

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John M

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23afdahlbo

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John M

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Dennis K (WA)

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