Farmall A with Siphon cooling system

Hello guys I have purchaced a 1940 Farmall A and it has a small coolant leak. I am not going to use the tractor enough to really tear into it and was wandering if Bars stop leak or one of the others would work being there is no water pump.

It MIGHT if you add it after you've got the tractor hot and circulating and run it for a while longer. The stuff tends to settle out and fill the drain pipe with its sludge.

without a waterpump it wont do any good it will just go to the bottom and plug the drain. Where is the leak. I fixed a leak at the top outlet where its soldered to the tank with rubber cement.

Don't know cantseem to find it.

Have you topped off the coolant? I'm wondering if maybe you don't have a leak at all but just the usual overflow after refilling. It will do that until it finds it's own level after a few heating and cooling cycles. The overflow is carried down a tube from the filler neck, along the edge of the rear of the fin tubing and empties into the front casting. If you're just noticing it in the casting or on the ground and can't find a trace of it above, that may be the source and is not a problem.

I have topped it off 2 times in about 8 hrs of use. I only fill it to the bottom of the neck and it has gone down both times to the top of the fins. I am not mechanically inclined and my neighbor showed me what looks like antifreeze on the bottom of the oil drain plug where it drips alittle. What is the average cost to have somthing like this checked out and is it worth it. If not what is a 1941 A none restored runs great with cultivators and 4 new tires worth in this condition?

John or ihallthe way bought his A from the same guy I bought my A from. This type of thing has him scared to death and he don't want to spend anymore money on it. I told him it could be the head gasket or those o-rings at the bottom of the sleeves and he doesn't want to tear into the motor.

I have used Bars-Leaks successfully in thermosiphon systems.

They are good systems but unfortunately they cannot operate properly when the water level falls to the top of the radiator core. The thermosiphon system relies on heavier cool water forcing lighter hot water over the top radiator hose into the radiator. When the water level gets low only enough that the top of the radiator is not flooded then there is not enough weight in the radiator to force hot water out the top hose from the engine. They only circulate with low water level as steam bubbles boil water out of the engine so the engine will run hot.

Now you've gone and scared him! (jk)

It depends where he's losing the antifreeze from. If he's losing it that fast, go at it in this order.

With the tractor having sat idle for a while (a couple of days is really good), open the upper petcock on the side of the oil pan. If you get a steady run of oil from there instead of a drip, it means the crankcase is too full. Close the petcock. Wipe off all around the drain plug and, with a container under it to catch what comes out just loosen the drain plug and see what comes out. If it's antifreeze at first, then there is a problem in the motor, which could be a) one or more o-rings around the sleeves, b) a bad head gasket, or c) a crack in the block or head. If all you get is oil from the drain, the motor is good.

That leaves the radiator and hoses and the castings for the inlet and outlet and their gaskets. All relatively minor. And you shouldn't be fooled by there being antifreeze around the outside of the oil drain plug. The fans on these little tractors kick up quite a breeze and will pull the antifreeze from a small leak right off the radiator and plaster it to the front of the motor where it will then run down, over the lip of the pan and drip from the lowest point (the drain plug). Also, when it's all done overflowing, the coolant level in the radiator will be lower than you might imagine. It's hard to describe, I don't have a measurement, but you can discern the tops of the tubes. If the crankcase was free of antifreeze, I'd give it one more run, with a tall kitchen trash bag over the grille to make sure it heats up well, and see if the level drops any further. If not, then that may just be his level.

If it drops lower or is, in your judgment low enough that the thermosiphon just will not flow, then it's time to look for leaks. Any obviously damaged areas are suspect. The seams between the core and the upper and lower tanks, the inlet and outlet necks are common spots. Look the hoses over carefully, especially around the clamps, as well as both in and out castings and the gaskets where they mate up to the motor.

One way to go at it is to have everything wiped down well. It might seem a little extreme, but you can take the fan and grille off before running it. A leak should become apparent before the motor overheats enough to boil over and do any harm.

That failing, take the radiator off and get it to a shop that can pressure test and repair it. The last time I took one in, it was $35 to find and fix the leak and resolder the overflow drain tube. Removing grilles, fans and radiators is part of the fun. I don't know that I'd pay anyone to let me do it, but I don't get into too many projects where I figure the cost of my time in.

We just got through cracking the oil plug and there is antifreeze at the plug. Not much not even enough to show to much oil in the motor but there is I would say less than a small coffee cup. John's setting in the corner with his head in his hands. He says no mre moneys is going into the old tractor.

Well give him a snort of somethin' to cheer him up.

I have no idea what's gone before or how much he has tied up in it or available to put into it, so I don't mean to be smart or disrespectful about it.

Nine times out of ten it's the head gasket, about $65, and a short morning's work with nothing more than the gasket and a few wrenches including a torque wrench, some gauges to reset the valves, and maybe a new valve cover gasket.

I would drain coolant and use straight water until you get leak fixed. An engine can live with a little water in oil but anti freeze is death for bearings. We used to drain tractors every night in cold weather and it is not a lot of trouble.

Tell him to put a price on it and advertise it. Sell it "as is." Hal

Well after dinner I think I have him ready to pull the head after Christmas. He said he don"t want to even see it for awhile so we will leave it in my shed. I had to change the head gasket on my old 40 H and its no big deal I may even dig into it this weekend as a Christmas present for him. I hope thats the problem. The tractor is a very strong runner with no blowby to speek of.

farmallhfan remember I am on this forum too. Leave that thing alone and let me get my thoughts together. We will look at it again after The holidays. To you other guys I have $1800.00 in this A now should I go on or get out while I can? farmallhfan gets sort of crazy when it comes to these old tractors and we joke all the time about whether they are worth the money or not. By the way hfan and others thanks for your thoughts.

alltheway come back over and we'll get out the cherry pop in about a half hour you'll be ready to tear it down and rebuild the whole motor. Just bring a signed blank check when you get here for the parts you need. We will call it tractor therapy.

if you think the problem is the head gasket, it is really pretty easy to swap that out. just put a new one in my A cause of an oil leak. new head & valve cover gaskets from Case-IH, can of copper gasket sealant from NAPA, basic hand tools, and you'll have it done in a morning. the book says torque head to 65 ft-lb but i think C-IH has changed recommendation to either 80 or 85, and that's what it took on mine to stop the leak.

Did anyone retorque the head lately?

No. the engine shows signs that it hasn't been touched in a good while

Well, you're welcome, and I can appreciate the point you seem to be at. In my experience, you're approachin' it right, too. Take a breath. Problems with a running machine can be frustrating, but these old girls are really pretty simple, and a lot of times the fix can be, too.

The first one I bought, I didn't go crazy but I probably put more into it than might be justified purely on the economics of it, but it was worth it to be pilotin' a Farmall again.

The next was an absolute basket case, got torn down to the last bolt, rebuilt stem to stern and repainted at a cost probably three times what it's worth, but that was a family tractor dear to my heart.

You're not in overly deep for a good running A. In my book, it would certainly be worth trying the head gasket over just dumping it.

I just take the pan off and then with a good lite you can look at all the sleeves and you will probably see the green color at the bottom of which sleeve it is leaking. Not that hard to pull the sleeves and install new o-rings. You will probably find the cavity around the sleeve built ip with lots of sludge that needs to be removed anyway for better colling. You could also add a waterpunp then try sealer and with the pump just mite fix the leak. The tractor is worth fixing.

Where's this tractor at - maybe someone (I) can give it a look?

Also remember it could be really simple, or it could be a crack, but take one step at a time and it will be worth it.

I would get the antifreeze out of there and fill it with water, or you'll eat the bearings up.

This tractor is in Hendersonville, NC

This is a late reply, but IF it leaks down no more than the top of the fins, then the overflow tube probably has a crack in it inside the tank at the point where it passes through the bottom of the tank to the outside. The overflow tube sticks up toward the radiator fill neck.