D9 18a

Hello Grizz and welcome.
Seems like you've touched on most the candidate sources for leaks but you need to add pin holes in the pre-combustion chambers to your list. Also cracked castings.
Water pump is a gear drive with mechanical seal and doesn't appear to have a separating cavity and weep hole.

Maybe get an air pressure check on the cooling system and see if you can judge how major a leak it has. Open something up to see what the condition of the water side passages look like. I would suspect that the liner seals would be the prime candidate.

I live 1000 miles from the D9 so we would have to be kind of prepared for a major job like changing liners.
How crazy would I be to fill the cooling system with engine oil if it is a liner leak??

For how long and how far?
Probably wouldn't hurt to go that 4 miles and get it loaded for transport. Don't know how long it would take to overheat. Take some doing to get the cooling system cleaned up again. Plenty of old time tractors survived using diesel fuel as coolant.

Yes, that's a problem....these old Cat's don't break down where you want them to.

Thanks for the input 😊 I guess that would tell me what else is working or not on it . I don't suppose ther is any other temporary fix for liner seals. and what are the chances of pulling the liners with out wrecking them?

I'm sure someone will recommend loading it up with one of the radiator stop leak products.....but you sure don't want that crap in the lube system.

Your not going to hurt the liners, they are thick wall and hardened.

bars leak in the oil passages .............arrrgh
where would I get the liner dimensions etc so I can spin up a tool on the lathe???

Interesting idea putting oil in the cooling system. What about making the move in cold weather, using very light oil, maybe 10 wt so it will flow through the radiator flues better. If it is a liner seal leaking, putting the oil in there might just seal it up when the top o-ring that's been exposed only to coolant gets a dose of petroleum to soften it up.😄

On the other hand, it's very likely that you could just fill it up with plain water and move it as far as you need to while monitoring the condition of the oil. A leak that fills the oil pan with coolant when it's not running might not make much of a problem during a short run.

A water pump seal might also leak a lot slower while running, just depending on what is the problem. I have had belt drive water pumps fail that I am confident were stuck and then damaged when the engine was first turned after a prolonged period (months) of sitting. With the seal element cracked like those were, you wouldn't get much run time before the oil turned to pudding.

If you pressure test the cooling system with the inspection covers off the side of the engine, you could possibly get an idea of what was leaking and how fast.

The engine is a D353 with a 6.25" bore x 8" stroke if you need to get the tooling ahead of time.

I live 1000 miles from the D9 so we would have to be kind of prepared for a major job like changing liners.
How crazy would I be to fill the cooling system with engine oil if it is a liner leak??

[quote="Grizz"]I live 1000 miles from the D9 so we would have to be kind of prepared for a major job like changing liners.
How crazy would I be to fill the cooling system with engine oil if it is a liner leak??[/quote]
BOUGHT DREAM, 38 FORD P/U, FLATHEAD 85, HAD FROZE & BUSTED. FILLED W/RERUN MOTOR OIL, STARTED 300 MILES HOME. EVEN W/ WINDSHIELD CRANKED OUT, GOT CHOKED & BLINDED IN 20 MILES, BUT RAN FINE!BE BLESSED, D9 19A