correct coolant for ford lehman 120

I cannot remember what kind of coolant is correct for this engine. I read ethylene glycol is preferred, and the coolant I have now is green. Anything else to know or specify?

Greetings,
Welcome aboard.

Colour is immaterial nowadays. Pick a good 5 year diesel-spec coolant.

Welcome!

Xsbank said:

Colour is immaterial nowadays. Pick a good 5 year diesel-spec coolant.

Welcome!

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And yeah, a lot of them are green. Mine is and I use it in that exact engine.

Mine is green and the concentrate was mixed with distilled water, apparently that`s important. If you buy 5L packs of it ready to use it is already diluted(? they use distilled/demineralized water).
That engine can get silting in the passages at no6 cylinder, leading to overheating, requiring an aggressive flushing. Is doing the coolant connected to that by any chance?

American Diesel recommended just plain old style ethylene glycol such as Prestone extended life because of the old engine design.

Yes plain old green ethylene glycol. Can't just use anything. All coolants are specifically designed for specific engine materials. The older spec coolants are fine for cast steel blocks with steel heads etc. the more modern engines with combination of metals require a different coolant to combat any chemical reactions between metals. It's not just about anti boil and anti freeze

Greetings,
Can't remember the particulars but also different coolant, I think, for sleeved and non sleeved engines or is it wet and dry sleeved engines????

For my Ford Lehman engines, Should I dilute the coolant 50/50 with distilled water?

Concentrated you dilute, pre-mixed you don't.


read the jug.

Yes, if you have to dilute what you have use DISTILLED water.

psneeld said:

Concentrated you dilute, pre-mixed you don't.


read the jug.

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Thank you, I’ll buy the diluted premixed antifreeze

That pre-mixed stuff is a LOT more expensive but it is more convenient.

ddefabry said:

Thank you, I’ll buy the diluted premixed antifreeze

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"For my Ford Lehman engines, Should I dilute the coolant 50/50 with distilled water?"

Distilled water YES! Pre mix NO, who knows what they use as OK ?

50/50 depends on weather you need the cold weather freezing resistance.

Antifreeze has less cooling ability so warm weather folks can choose 1/3 antifreeze , 2/3 distilled water.

Your water pump will still be lubricated and the corrosion goodies will do fine to protect the engine.

More BTU can be passed with the higher water content in the mix.

AS your antique has a very low pressure cap, usually under 5 lbs, there is nothing gained by using a high temp boiling point antifreeze as cars do.

Handy comparison chart: