Farmall 300 coolant in oil pan?

Hello-

I have a Farmall 300 row crop tractor with the C-169 engine. This past spring when I changed oil, I noticed maybe a cup of green coolant came out first before the oil when I removed the oil pan drain plug. Well, I had other tractors I could use, so I put new oil back in the engine and put the tractor back it the shed until now when I had time to work on it.

I drained the oil this weekend, had some green coolant in oil pan again. I have removed the oil pan and wiped up all oil in the underside of the engine and crankshaft area.

Read that you pressurize the cooling system and wait for the coolant leak to appear. So I did this, pressurized to 5 PSI. Well, my radiator cap leaks bad and had small radiator leak, so that option is out until I can plug the radiator hoses and re-pressurize the system.

Since draining the oil and wiping everything down this weekend, I am seeing green coolant leak into crankshaft area above the camshaft, without pressure in the cooling system, it takes overnight for the coolant to reappear. I wiped off the camshaft 2-3 times now and the coolant seems to be dripping in the same spot above the camshaft and no where else in the underside of the engine. Coolant appears to be dripping from an oil return hole about size of a dime in the block above the camshaft between the 2 lifters for the 2nd cylinder from the rear of engine.

Can anyone give me an idea if this appears to be a cracked head, cracked block, or bad head gasket? Possibly what I should do next? I did do a compression check last summer and noticed nothing odd about the readings between cylinders. Any info is greatly appreciated. Thanks!

-Jesse

Don't know if that is a wet sleeve engine or not but good chance it is and it could be a seal o-ring that has gone bad

No luck on that one I’m afraid. The 300 uses a dry sleeve engine.

since you have the pan off i would remove the valve cover and rockers and pushrods. then i would wash it all down from the top and use brake
clean to get it dry in pushrod area. then let it sit and see if you can spot the leak with a good light. maybe head gasket or crack. appears like its a teardown but good to know what you are chasing.

300 with the C-169 engine is an overbored H, 3-9/16" vs 3-3/8" for H. IT HAS CYLINDER BORES cast into the block plus sleeves. There's also a ridge on the OD of the sleeves that fits into a recess or counterbore around the cylinder bores that traps the sleeves into the cylinder.
There's no way antifreeze can get out of the block except thru a leaking head gasket, or a crack in the block somewhere. Where you wiped coolant off the cam is a good place to start looking.

Your comment about leaky o-rings between sleeves and block is TOTALLY off the reservation! IH did make a couple wet sleeve engines, A,B,C were wet sleeve with o-rings. IF you don't know what your talking about it's best to NOT POST.

Pull the side cover off the engine as this will get you to the lifter area and see more of where it may be coming from , then the next stop is pull the valve cover . You may get lucky and only have to deal with a head gskt and reface the head . Doing a pressure check of the block can be done BUT you will have to make up a deck plate to block off all coolant passages . You can also do your own head check by making up one plate and some thick rubber for a gskt and block off the T stat with a plate after fillinf with water and a way of applying air pressure of around 20 PSI but you have to have cut outs so yo can look in the chambers of each hole If you pull the head also check each sleeve for even stand out , if one is higher then the rest this will cause a coolant leak.

How long have you had this tractor? Any recent work
been done to it that required removal of the cylinder
head? At any rate I would remove the valve cover and
look under there especially looking around the push
rods with a good light. If the head has been off
recently see if the head bolts are torqued to spec. If
they seem to tighten some I would put the pan back
on run the engine to get the temp up then retorque it.
If you want the tractor to be as reliable as possible
you will want to continue to diagnose how the coolant
is getting in the pan, most likely it is the head gasket .

(quoted from post at 11:58:05 01/13/21) How long have you had this tractor? Any recent work
been done to it that required removal of the cylinder
head? At any rate I would remove the valve cover and
look under there especially looking around the push
rods with a good light. If the head has been off
recently see if the head bolts are torqued to spec. If
they seem to tighten some I would put the pan back
on run the engine to get the temp up then retorque it.
If you want the tractor to be as reliable as possible
you will want to continue to diagnose how the coolant
is getting in the pan, most likely it is the head gasket .

Click to expand...

I have had the tractor for about 5 years now. No recent engine work has been done to this tractor. I bought it from the neighbor, he did not use it much at all before he sold it to me, as he had no equipment that was small enough for it anymore. They are a large dairy farm. Used it alot up until last spring when I changed the oil and found the coolant in pan. Will check the head bolt torque. Thanks!

-Jesse

If you take the time to read what I said you would not be attacking me like this. If this is how your going to be don't answer my post period

You were talking like you thought you knew what you were talking about. But you didn't. In the future if you are not sure, then don't post anything, inaccurate info really is worse than none. Plenty of people on this forum that know EVERYTHING about these tractors. Pete23, and a dozen others.

I hope to get back to the diagnosis on the tractor this weekend. Thanks so much for the info thus far. Will keep the group informed.


If I do have to take the head off, would a head gasket issue be easy to spot where the coolant may be leaking?

Also, when re-installing the rocker arm train, is there a torque spec. and sequence or do I just tighten down all bolts evenly until tight? Thanks

-Jesse

Every time I have removed a cylinder head and found a leaking head gasket, it was evident by the discoloring on the block/head/gasket. You should see the path the coolant was taking. It would also be good to check both the block deck and the head sealing surface with a good straight edge and feeler gauge checking for areas where you can see light/pass the feeler gauge between the flat edge and sealing surface. There are videos on the internet showing how to perform this and it is fairly simple, as long as you have a good flat edge, that is known good. The amount the head is allowed to vary out of flatness will be listed in the service manual that I do not have with me right now. Usually, on a 4 cyl cast iron head, I would like to see less than .004' end to end and .002" side to side, but I don't remember if those are IH specs for that engine.
Head bolt torque on that engine is 70lb/ft but I don't have the rocket bolt torque in front of me. Most just know how tight to tighten them and then set valve lash .017 for both intake and exhaust with the engine at operating temp.

Again read what I said not what you think I said. I said if it is a wet sleeve engine. When I posted I did not have the time to look in the manual so leave me alone from now on and I sure as heck will NEVER answer you again

Hello Everyone-

Well, I found the problem tonight. Had to take off the thermostat housing and make a block off plate, plus plug the top of water pump and lower radiator hose. I pressurized the block to about 7.5psi. By shear luck I was looking at the top of the cylinder head and saw some bubbles coming out under the grease and oil. Cleaned off the spot and can see the crack and bubbles plain as day.

So, I think the coolant was leaking on top of the head, then draining down the pushrod oil return holes and leaking past the lifters and dripping on top the camshaft where I saw the green coolant.

If you look close, the crack runs from the center of the bolt on bottom of picture up to the - between the 9 and R in the part number.

Does anyone know if this head is repairable, or am I better off finding one that isn't cracked? Thanks

-Jesse

So, I think the coolant was leaking on top of the head, then draining down the pushrod oil return holes and leaking past the lifters and dripping on top the camshaft where I saw the green coolant.

Here is another case where you need to diagnose the problem before you just pull things apart and start throwing new parts at your tractor. Sure glad you found the problem. Good luck as you start looking for a good cylinder head.

Before I tore anything apart, I would try some block sealant. The stuff I used worked with water, so you will have to drain the antifreeze and put it back after the treatment.