ZTU Radiator

kermkep · Apr 29, 2016

I have a 1944 ztu. When I run it long enough to get good and warm, not hot, the radiator looses coolant out of the overflow shortly after I shut it off.
It runs good other than that. Does someone have an idea as to what might be causing this.
Also is this a pressurized system. There is never pressure on the cap.

Thanks in advance.

molinegb · Apr 30, 2016

Pressurized cooling systems in MM Z's started in 1952. You may have bad head gasket,head or
cracked block. Is there bubbles in coolant? Radiator been cleaned?

molinegb · Apr 30, 2016

To add waterpump baffle may be bad and not moving coolant through system.

Alan K · Apr 30, 2016

Have you looked at your thermostat? If there isnt enough of a bypass in it, it can cause
something similar. Also might be a chunk of rust in the head that stops part of the flow of
coolant to the thermostat when it is running, then when the engine is off and the coolant
expands a little more it ends up out of the overflow. Not sure how full the radiators were
supposed to be but you could try no more than an inch or two over the core. If there is too
much coolant, when it expands it has to go somewhere.

kermkep · Apr 30, 2016

What degree thermostat should be in this tractor?

unc · Apr 30, 2016

I had a similar problem with my 47 ZTU. I solved it by installing a 2n/9n/8n thermostat about half way up the top hose. It now runs and cools like it should( also added a temperature gauge). Since then, someone suggested that the by-pass hole in the new style thermostats needs to be bigger. Food for thought. I use this tractor for cutting grass, and it will sit at 180° all day long, with the coolant just below the bottom of the rad neck. Unc

molinegb · Apr 30, 2016

Before you get a thermostat just try without to see if problem still exists.

T.R.K. · Apr 30, 2016

You are running 50 percent Ethylene Glycol mix for antifreeze mix aren't you?
I had that problem with foaming in an R with Peak antifreeze in it once, but its not ethylene glycol, its some other chemical. It would burp antifreeze like crazy.

Other thoughts:
Are you sure the baffle behind the water pump is in good condtion? It won't move near as much water if it isn't.

How full are you filling the radiator? Without an overflow tank, your cold water level probably needs to be 2 inches or more below the cap so there is room for it to expand.

kermkep · May 1, 2016

Thanks for all the suggestions. Yes the mix in the radiator is a 50/50 mix. I'll look at all the other
things and make a reply when I find the problem. Thanks again.

thethresherman · May 1, 2016

My RTU used to give me fits until I made sure to mix distilled water with the antifreeze. Been doing real well ever since. That was about 3 years ago. I had mixed soft water with it before.

Roger H MI · May 1, 2016

It sounds like someone took a radiator out of a later model R at some point or
had a pressure filler neck installed to yours. It could be a thermostat if the tractor
still has one. Most farmers threw them away and ran them without. I would suspect a
partial plugged radiator. You might try back flushing. Also check to see if water is circulating
by looking at the flow through the filler neck. Just some suggestions have fun.

ZTU Radiator

kermkep

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molinegb

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molinegb

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Alan K

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kermkep

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unc

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molinegb

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T.R.K.

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kermkep

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thethresherman

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Roger H MI

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