My MD radiator bursted tonight....why?

SW EM

Member
I am in the final stretches of restoring my 1950 MD for RPRU this summer, and I had a setback this evening when my radiator dumped itself on my garage floor immediately after stopped the engine.

This was the first time I ran the tractor with a thermostat in (new from the CNH dealer). I was impressed with how fast it warmed up and how well it ran on diesel when I switched it over. I drover it around the yard some and let it idle for 10 minutes. The water temp guage was in the middle of "run" the entire time.

I switched the engine to gas for 5-10 seconds before shutting it off, then I switched the lever to the diesel side (as to not warp the starting valves). As I was dismounting I heard what sounded like a bucket of water being poured on the floor and I saw it was my antifreeze coming from my radiator area. It was a mess....

Tomorrow morning I will remove the radiator and check to see exactly where it came from, but for now I would like to gain more of an understanding of what could have caused this.

I was given the radiator from a friend who had it checked over and resoldered by an experienced radiator shop. He was going to put it on his M but his shop burnt down and he lost everything.

I will post again tomorrow on what I find. If you have any ideas or suggestions I'd be glad to hear them.
 
No very familiar with how hot the diesel runs, but I worked the snot out of my Super M pulling a 13' model 37 disk and she never gets above the center of the cold mark maybe a little closer to the green but never in the green
 
Would first check to see if air was trapped in system with fill up after installing the thermostat and for correct thermostat and radiator cap if fluid is coming from the radiator overflow. If above is okay and radiator itself didn't fail would check for compression getting into coolant area.
Someone will tell you not to shut off on gas but that's not your present problem.
 

Either a repair in the radiator was marginal and let go as you shut it off and the heat spiked just a little or it came out the overflow.

The only time I've had a radiator burst is when a head gasket let go with 75+psi of boost going into the engine.
 
the "why" would make me think rad cap not releasing pressure, and did you have the proper lb. cap. did you look in rad with it running for bubbles? the temp needle is normal to sit on the U in RUN position on guage. temperature will climb a bit on a hot engine also not cooled. also you can see when the thermostate opens when filled as you will see the guage drop off. i am just thinking that it may have been air locked because you saying the needle was in the centre is too high for tractor not under load. its not nesssesary to switch back to gas, diesel idling will cool quicker. and the little gas valves can stay seated to dissipate heat. but not gonna blow up the rad.
 
Thanks for all the responses. It must have been air trapped in the system because the radiator holds water now. I suppose the next time I start it I will leave the cap off for a while to let the trapped air out. This is the first time I've had this happen. I have a new radiator cap from Steiners I will put on it too.
 
only fill it to an inch above the cores of the radiator (down a couple of inches from the neck) or it will puke again.. Jim
 
Haha sorry for keeping you in suspense guys! It turns out the radiator did not burst. It must have been an air pocket pushing coolant out of the overflow tube. I had never seen that happen before. It dropped a gallon in 3 seconds....I suppose it can do that when under pressure.

I reinstalled the radiator and drove the tractor with the cap off to let it "burp". Operating temperature was directly in the middle. The coolant didn't settle much during that time, and nothing happened when I shut it off...

The next time I drive it around I will put the cap on and keep and eye on the overflow tube. I have never had any of my old tractors do this after re-filling the radiator before.
 

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