Non- Pressurized Cooling System

[oldfarmkid]

I'm sure like many others, it took me a little time to figure out I had a non - pressurized cooling system on my 1940 - H. I have it all sorted out correctly now, but info is a bit lacking. Bought a service manual and operators manual, all info is for a pressurized system. Most parts dealers don't carry the correct thermostat. Did International ever put out information on non - pressurized system with part numbers for correct temperature gauge ? When I try to research it, all I get are informational points of what is the correct radiator cap.

Thanks

Tim

[oldfarmkid]

Any thoughts as to why international installed a waterpump and thermostat, but made the choice to have it non pressurized. Until I got this tractor I was under the impression that anything that had a waterpump and thermostat was a pressurized system.

[Don McCombs]

Why do you suspect that it is non-pressurized?

[oldfarmkid]

Well... no suspecting, it is. Radiator flange for cap same as gas tank. Gas cap and radiator cap interchangeable. Engine at operating temp. and running,reach up and remove cap, no pressure. From what info I could put together, perhaps flawed, thats why I'm asking. Non pressurized systems use a thermostat that begins to open at 130 deg. fully open at 155 deg. Pressurized system begins to open at 160 deg. fully open 190 deg. I think. The temperature gauge is made to match the thermostat. Thats why mine seemed to always run to the hot side, someone had installed an incorrect 160 deg. automotive thermostat. Was showing temperature towards the hot side because temp. gauge was made for thermostat that begins to open at 130 deg. not 160 deg. It would show this hotter temperature after just 3/4 mile in road gear. All temps verified with laser gun type measurement device that is accurate, as long as it has a good battery in it. Installed proper thermostat, all temps, now continuously where they should be, according to Case International parts spec. sheet. I have read posts from others that have been down the same road as me with their older farmall- H, but never any copies of McCormick/ International data sheets or operators manual that give details on non pressurized system as they do with a pressurized system. So either this is how the factory made it or someone years ago went to a lot of trouble installing a non pressurized radiator with matching temperature gauge.
Whats your thoughts, did International produce the older 1940 - H this way, or did someone do an excellent job jury rigging this thing. To me it all looks original.

[Jim Becker]

Using a pressure cooling system and a water pump are two totally independent design decisions. I fail to understand why anybody (seemingly everybody) would think that having either one would require use of the other.

The original Farmall H, as released to production in 1939, used a water pump with a thermostat but was a non-pressurized system. In late 1942 at serial 115030, they changed to a pressure system so they could reduce the number of tubes in the radiator, thus conserving copper and brass. Your temperature ranges for both thermostats match the numbers given in the H parts catalog.

[oldfarmkid]

Well Jim, my excuse is, I worked in the aviation field, navigation, communication, back up power systems and some military time, for 35 years. But now that I'm retired, time for the good stuff. Thanks for verifying some information and giving some new. Do you know of any information put out by International on non pressurized cooling systems other than just the temperature ranges on a parts list.

Thanks

Tim

[Jim Becker]

What kind of information are you looking for?

[oldfarmkid]

Main question is, do I fill the radiator to the same level as they give for the pressurized system. Also, is the radiator cap vented like the fuel cap. If it is I need to replace it. Seal is good, outer surface looks good, but under the cap solid rust. Thats It.

Thanks

Tim

[John *.?-!.* cub owner]

On a no pressurized system the overflow tube in the side of the neck provides the vent. On a pressurized system it also provides venting if pressure gets to high.

[oldfarmkid]

Yep, I can see that now. Not having all the extra parts and pieces of a pressured cap. Tube is exposed continuously inside the neck to vent or expel overflow.
Thanks John