Farmall H- what should I see when I pull the radiator cap?
 

I'm trying to figure out if something's wrong with my H's cooling system or not. It has me stumped because I'm not sure if what I see in the radiator is normal or not. Tractor is a 1946 Farmall H. Water pump cooling system. The system itself seems to work flawlessly. The tractor runs so cool you can put your fingers just below an exhaust manifold port and hold it there without getting burned.

The thing perplexing me is what I see in the radiator with the tractor running (and just after shutoff). When off and cold, looking into the radiator, its normal green coolant. When I fire the tractor up, I can very obviously see coolant coming into the radiator from the pump. If I understand correctly coolant enters the radiator from the top and then flows down. I am unsure as to whether or not I'm supposed to be able to see the flow of coolant this well, nor am I sure its supposed to be such a strong flow. The coolant itself turns from transparent/translucent green to an opaque green, though I would expect this with the power of the flow into the radiator. Perhaps my waterpump was replaced/rebuilt in the recent past?

It gets more confusing on shutoff. After shutting it off, a thin layer of white foam settles at the top of the radiator. Again, this is probably due to the power of water flowing into the radiator. Is my water pump just really strong??

I've been looking for signs of a blown head gasket, but have come up with nothing. The oil hasn't turned white at all, and the coolant stays green. The cylinders don't ever fill with coolant either, and the exhaust never smells sweet. Nor do I get any smoke from the exhaust. The machine performs just fine, and the cooling system itself keeps the engine very adequately cool.

So at the end of it all, is this normal operation??? I have no idea what it is supposed to look like in the radiator. I can get a video of it if that would help. If I had to guess, the tractor just has an abnormally strong water pump, but I'm not sure.

Edit... I just had a thought.. IIRC these tractors have thermostats in them, and I know they can get stuck. Perhaps my thermostat has gotten stuck wide open, causing it to have full unrestricted flow through the radiator?

If you're not using coolant I wouldn't be concerned about a head gasket.

Yes, you may have problem with a stuck thermostat or a missing one. I know 350 is missing one, will remedy that this winter.

As for and abnormally strong water pump, what's your idle speed? If memory serves should be about 425 rpm.

Its not gonna be an abnormally strong pump if its the thermostat, the pump is most likely normal. If my thermostat is stuck or missing, that's why I'm seeing such a large volume of flow through the top of the radiator. The more I think about it the more it makes sense, I nearly forgot these machines had thermostats.

Any downside to leaving it be? I know its not right and I should get it fixed but I don't have the time or shop space to do it currently.

"Leaving it be" may mean you are encouraging abnormal wear and tear running the machine well below optimal operating temps too often. It can't be a big job replacing the thermostat, so just do it!

Depends on a couple things. Thermostat is in a case just before the return line. Seems to be decently accessible with the hood removed, however if I need to drain coolant to do this it's not going to be an easy task...

Plus on such short notice I don't have a thermostat handy, nor a new gasket for the case its in. Not sure if you can free up thermostats or not but I'd rather replace,,, making a gasket is easy enough though. Is it a generic thermostat, or a specific one for IH?

If your seeing a good flow in the rat eye ate her on cold start up, it is prolly because da thermostat is MIA, or plum stuck open.
Prolly been that way for 40-50 years, but it is nice to have it come up to operating temp as it helps to evaporate the condensation in the crankcase that builds up. Especially now a days as most people are not working these old horses full gallop on a picker of plowing.
Did yer H have shutters? that helps to heat them up.
also I'd recommend a 180* stat as the 160's really don't get them warm enough to do much good.
Also you cannot use the usual car/truck thermostat it needs to be for a Farmall, as they are taller.

Buy the right one for your application. There is a drain from the bottom of the rad to easily catch the coolant.

I recommend replacing/installing a thermostat. The engine was designed to run within a certain temperature range.

Draining the coolant is fairly easy. There is a drain at the bottom left of the radiator, you will need to turn the wheels out of the way. You can use a 5 gallon bucket to catch your coolant.

Please don't make excuses, Check with your local deal, check e-bay, amazon, they're readily available. Yes they are specific, a thermostat from your old Chevy will not work.


Side note,
If you run without a thermostat you risk running your engine too cold causing extra wear and tear on the internal,components. You also, when running under heavy load for an extended period of time, run the risk of over heating the engine as the coolant doesn't spend enough time on the radiator before returning back to the engine.

I'm not trying to "make excuses" to not do this. At this point I very much want to get this done as I want this machine to run as best as it can and not fail prematurely. My problem is quite simply that I do not have the time. I did have all day today but on such short notice there was no way I'd have a thermostat here to get the job done. As of now I am unsure when I'll have another free day to make this repair, plus with cold weather on the way its going to be difficult to find a day when it isn't freezing outside. I want to do this ASAP because I had planned to use the loader for snow removal, and if it's running too cool now, boy is it gonna be running cool when its 10 degrees out.

And I apologize for not knowing the ins and outs of these tractors enough to know where the radiator drain is. Yeesh. I just bought this thing a month ago. I appreciate the advice from all of you, but keep in mind I'm not an expert on these! I'm trying to learn, not be criticized for not knowing things!

Thank you for this advice George. That's pretty much what I'm assuming, either its stuck or missing entirely. It does not seem that the tractor has ever had shutters mounted on it. There is no linkage for it anywhere as it seems.

As for the thermostat I will look for a 180 degree one instead of 160. Thank you for the advice.