Farmall A cooling system

[badfxr]

Just picked up a '41 A with woods belly mower to mow my small pasture. When I brought it home, I checked all the fluid levels. The coolant level was fine, and the fluid looked nice and clean. I drove the tractor around for maybe 15 minutes or so, and when I parked it, I could hear the coolant boiling. After letting it cool down, I checked the level, and it was low. I added some to it, started the tractor, and checked for flow. I couldn't see any coolant flowing at all. Can I assume I have a bad water pump?

Looking back to when I was considering buying it, the previous owner pointed out that he put on a new fan. Also, when I drove it at his place, I was going to check the coolant flow, but when I grabed the radiator cap to remove it, it was very hot (after only about 5-10 minutes) and I didn't open it. I had just assumed that he had the tractor running before I got there, and that was the reason it was hot. I went back to look at it a second time, and wanted to check it then, but I got wrapped up into looking at other things and talking to the owner, and I forgot. Now I'm wondering if there was a cooling issue before, since he had replaced the fan. I'm hoping it's not a radiator, as they are expensive and would cancel out the good deal I thought I got.

 

[Sunkistdds]

Most of the old IHs relied on convection for a lot of what got done. Pumps when there were not volumn focused from what I have seen first hand. They had radiators bigger than needed if a faster pump were used. Just part of the over engineering of same that makes them still be around today.

Did you check the temp of the coolant? I have an old 350 utility that always sounds like it has overheated when shut off but the coolant temp is under 200. I have a Cub an H and an A also.

If the coolant temp is high after running long enough to get a flow and engine to full temp, I might suggest having a radiator shop do a flow test and if needed a cleaning before I dunked for parts.

Cap is usually not a prob, but u never know on old iron

 

[badfxr]

I have not checked the coolant temp, because it sounded like it was boiling in there and didn't want to remove the cap. There is no temp gauge on the tractor. I'm assuming the cap is not a problem, as it's a non-pressurized cap. Unless someone updated to a pressurized system but didn't update the cap???

You say you have an A. Can you at least see some coolant flow when you remove the cap?

 

[Nat]

A '41 didn't have a water pump. It had a thermo-siphon system. Hearing water gurgling in the red is common. Most of them had a set of shutters to block the rad. It may be that they are stuck shut, but if not I would rely on the temp guage not just my ears. HTH,later, Nat

 

[badfxr]

If the tractor doesn't have a water pump, what is the unit that bolts onto the front of the engine that has a pulley, that the lower radiator tube runs into? Also, what would the part at the bottom of this page be? It says water pump for A?

International Case-IH A Cooling tractor parts

Where are the shutters located? I'll make sure I check that today.

 

[RickB]

If the tractor doesn't have a water pump, what is the unit that bolts onto the front of the engine that has a pulley, that the lower radiator tube runs into? Also, what would the part at the bottom of this page be? It says water pump for A?

International Case-IH A Cooling tractor parts

Where are the shutters located? I'll make sure I check that today.

Not one single Farmall A left the factory with a water pump. Maybe you have a later engine installed, or maybe you have a Super A, which I believe had a water pump. Does your tractor have hydraulics? If so, it's for sure not an A.

Just because some aftermarket parts jockey sells a water pump that he says fits a Farmall A doesn't mean it does, or the seller knows anything about either the pump or Farmalls. It is just as unlikely that the radiator listed will fit all suggested models. Some are pressure systems with pumps, some are not.

Shutters are located directly in front of the radiator.

 

[BobG_in_VA]

Not one single Farmall A left the factory with a water pump. Maybe you have a later engine installed, or maybe you have a Super A, which I believe had a water pump. Does your tractor have hydraulics? If so, it's for sure not an A.

Just because some aftermarket parts jockey sells a water pump that he says fits a Farmall A doesn't mean it does, or the seller knows anything about either the pump or Farmalls. It is just as unlikely that the radiator listed will fit all suggested models. Some are pressure systems with pumps, some are not.

Shutters are located directly in front of the radiator.

As previously stated, Farmall A's do not have a water pump, but use the thermo siphon method of cooling. You have to remember that a water pump engine pumps cool water thru the engine till it runs back into the top of the radiator to start the cycle again...a thermo siphon uses the engine heat to make the warmer water rise to the top of the engine, then run DOWNHILL back into the radiator, cooling the water till it reaches the bottom of the radiator, which is then drawn back into the lower part to the engine as the warmer water rises to the top...the radiators and hoses (top radiator hoses) look different on a siphon. On a water pump engine the radiator is taller and the top hose connection on the radiator may be higher than the top of the engine. In a siphon style the top of the engine is higher than the radiator as the hot water coming out of the engine runs downhill back into the radiator...hope this make sense. This type of cooling system works pretty well but you can't have any pressure type rad. caps. Oh, usually shutters were only found on the distillate type of Farmalls...ie. start on gas and then change over to kero. (you closed the shutters to heat the engine up enough to get the kero to run it...). you won't find shutters on a gas only engine....BobG in VA

 

[Nat]

badfxr, if you notice in the link you added to the post it stated the 123 cu in engine. An an A had a 113 cu in engine. Now a lot of old tractors have had engine changes, and even if yours is origional, the fan pulley will look a good bit like a water pump, but will only be a fan hub the is powered by the crankshaft.
As Bob stated a thermo siphon works well just as it was designed to do. The water after picking up the heat from the engine will rise and cooler water from the bottom of the radiator will be drawn into the engine to replace the heated water that has risen to the top. HTH, later, Nat

 

[Soundguy]

I'd also like to add that many thermosyphon systems work worse if too much coolant is added tot he water.. I've notice dthat on the yanmar.. they seem to like 70/30 vs 60/40

probably not an issue here.. just throwing in my 1.5 cents.

soundguy

 

[RickB]

In a siphon style the top of the engine is higher than the radiator as the hot water coming out of the engine runs downhill back into the radiator...hope this make sense. BobG in VA

Actually, it makes no sense. In a thermosyphon system, the heated water rises from the engines water outlet to the top radiator tank, the highest point in the system, and the place where the hottest water is found after circulation begins. Cooling fluid drops down through the rad coils and is drawn back into the engine.

By your description, the hottest coolant would be trapped in the upper part of the cylinder head and not convect at all. Heated fluids will not travel downhill on their own unless they cool and become more dense.