Explain this

[37 chief]

I was mowing a couple days. Radiator sprayed a stream of Coolant on the hot manifold, causing what look like smoke. I jumped of and saw a stream of coolant coming from my radiator. Took the radiator to where I bought it. Most of this I have already posted. Now the rest of the story. The shop pressurized the radiator to 15 lbs. no leak. They said the top tank was bulging. I didn't notice this. They removed the top tank and straightened the tank, and reinstalled it. I took my JD radiator cap to the shop. They pressure tested it. It didn't release until over 25 lbs. The cap looked good. Apparently my radiator was being over pressurized. They gave me a new 9 lb cap, and my radiator back, at no charge. I know I saw a stream of coolant spraying from my radiator. I guess this is one of these times when something can't be explained. I lost a couple days mowing, a gallon of JD coolant, and added 120 miles to my pickup. Stan

 

[SVcummins]

Maybe a hose leaking ? Did you shut the tractor off when you saw the leak to make sure it was coming from the radiator?

 

[Steve@Advance]

I suspect once the radiator is hot and under pressure the leak will show again.

But maybe with a lower pressure cap it will not, just have to see what happens.

Isn't this the aftermarket radiator? Some of those come with a non standard cap neck. It takes a cap unlike anything available here and if you do find a cap that fits the spring may be too loose or too tight. Not sure what the solution would be other than having a standard cap neck soldered on.

 

[old]

They did not tell you the whole story. The tank was expanded so good chance there was a crack but they did not tell you that part

 

[37 chief]

I got off real quick, because I thought it was smoke. As soon as I got down, I realized it was coolant, on the hot manifold I did look at the radiator, and saw a stream of coolant coming from it. They did say the tank seam didn't look good. I am sure they think I'm a crazy old man. I know what I saw. Stan

 

[SVcummins]

Probably when they straightened the tank they hopefully soldered the leak shut

 

[Traditional Farmer]

Tractor must be getting hot if pushing the upper limits of a 25lb cap,thermostat stuck?

 

[MarkB_MI]

> Tractor must be getting hot if pushing the upper limits of a 25lb cap,thermostat stuck?

Not necessarily, if the radiator was fairly full. The coolant will expand, raising the cooling system pressure higher than vapor pressure alone would cause. To put it another way, if you fill your radiator to the filler neck, coolant will overflow almost as soon as the engine is started, even though the coolant is still relatively cool.

 

[Traditional Farmer]

Maybe if its a newer tractor I don't run them but most of my older tractors I can run with the cap loose and 0 lbs pressure, none will push water by a 7 lb cap and he said a lot of water was coming from the radiator so a lot of water isn't just a little being pushed out for expansion.Water may have been coming from around the water pump shaft hard to tell where water is coming from with all the steam.I'm betting his problem is going to show up again.

 

[Stephen Newell]

Could it have sprayed the stream from the cap? Like old faithful from time to time when the pressure is up it spews a stream.

I'm wondering what is wrong with the cooling system that would cause it to build that much pressure. Have you checked the coolant with a hydrometer? Too little antifreeze can cause overheating.

 

[blue_tractor_man]

I would think that it would be no problem for steaming water to build up 25PSI and blow out a radiator dedigned for less. My 1964 tractor came with a 4 lb cap and I changed it to a 7 lb cap. Believe it or not, it used to boil over with the 4 lb cap, but not with a 7 lb cap. I figured hoses and replacement water pump seals could handle 7 psi. So far so good.

 

[miangus]

That kind of stuff happens my 4020 got hot baling where it doesn't work to hard. It was low on coolant and I couldn't figure out why. It seemed to be leaking at the cap, installed new cap, still leaked. After careful inspection of the radiator neck I noticed the edge was bent up just enough so the cap didn't seal. When I had the hood off (actually just lifted up) to change the rubber return lines I had bent the lip with the edge of the hood. Glad you found the issue. I agree with the others regarding a slight crack in the tank seam that hopefully got re-soldered. Sounds like you got good service.

 

[MarkB_MI]

> Maybe if its a newer tractor I don't run them but most of my older tractors I can run with the cap loose and 0 lbs pressure, none will push water by a 7 lb cap and he said a lot of water was coming from the radiator so a lot of water isn't just a little being pushed out for expansion.Water may have been coming from around the water pump shaft hard to tell where water is coming from with all the steam.I'm betting his problem is going to show up again.

Based on the original post, I assume the tank is detachable from the radiator core, and pressure was sufficient to open a gap between the two.

If you fill any of your tractors to the filler neck, the radiator is going to overflow. That's the nature of water: it expands when it's heated. And since water is relatively incompressible, if the radiator cap can't release something else is going to give. If not the radiator, it will be a hose or gasket somewhere. Now I don't think Stan overfilled his radiator, but even if it's not full it needs to vent as the coolant warms and expands. And if it doesn't vent the displaced air in the tank, the pressure will rise until either the coolant stops expanding or something blows.

 

[Bob Bancroft]

My CaseIH 7240 has a "coolant recovery system", which, in my opinion, is just asking for trouble. Every time it cools down, it sucks coolant back into the radiator from the tank. Then every time it warms up, it builds pressure, and pushes it back out.
One winter day I headed for the field with the chisel plow. I made it out across, and half way back something erupted. It was steam/vapor, not smoke. I idled back to the barn, where I found coolant all over, but no leak! After messing with it for a while I still couldn't determine anything. I replaced the original 15# cap with a 7# one. This was a year and a half ago. No issues since. My only theory is maybe frost developed somewhere in the recovery system, and caused a pressure back up, before thawing? I do remember I didn't warm up the tractor as much as usual that day. More mysteries!

 

[jd man wis]

I would think that it should never get that high of pressure in the radiator. I'm think that as it warm up and things expand that there is a head gasket leaking compression in to the coolent some were. Check with the cap off with it running for bubbles in the radiator and let it warm up to see if it gets bad.It might not show up at frist tell it warm up and things expanded.

 

[Traditional Farmer]

I understand all that but to reach 25lbs the water would be a very high temperature guessing 250 plus tractor shouldn't be running that hot to start with,as a normal tractor has to have a thermostat to get up to around 180.My Oliver 1550 diesel I bale with has a 0 lbs radiator cap,its filled almost up to the neck of the radiator,even after baling the water is basically in the same place.His motor is getting way too hot in the first place it appears to me,but of course he'll see once he uses it again.

 

[ss55]

If the radiator shop removed, straightened and re-attached the top tank, they probably pressure tested the repair too. I would run it now.

The bad radiator cap may have over-pressured the old radiator too, and helped destroy that radiator too.

 

[kencombs]

shortest and best answer.

 

[MarkB_MI]

> I understand all that but to reach 25lbs the water would be a very high temperature guessing 250 plus

You say you understand it but clearly you don't. Nor do I know any way to further simplify it for you.

 

[Traditional Farmer]

Yep cracked head or head gasket most likely with that high of pressure.

 

[Traditional Farmer]

I'm curious how many old tractors with mechanical issues have you ever actually worked on?

 

[kevinstuff]

I bought an old IH scout , 345 V8 st an auction
It had new radiator , the coolant was rusty and it overheated
often , had no leaks , finally took water pump off ,
and to my surprise , the water pump impeller
had completely rusted away , the pump didn’t leak at all
when a coolant flush and new water pump , solved
that problem . Also look for old hoses that may collapse
when hot .