Farm Equipment - 6080 coolant disappearing from overflow

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6080 coolant disappearing from overflow

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=195009
Printed Date: 08 Oct 2025 at 3:24am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: 6080 coolant disappearing from overflow

Posted By: ssefick
Subject: 6080 coolant disappearing from overflow
Date Posted: 06 May 2023 at 8:41pm

Coolant is disappearing from the overflow.

No coolant in the oil - not making oil and no mayonnaise in oil.

Maybe a new radiator cap? Maybe I am being overly cautious?

Anythoughts appreciated.

Replies:

Posted By: SteveM C/IL
Date Posted: 06 May 2023 at 8:49pm

Tank and hose are sound? I had a cracked tank before on another series.

Posted By: KJCHRIS
Date Posted: 07 May 2023 at 2:39pm

Does the coolant level get low enough that the tops of tubes are visible? If not it isn't low.

Does it have an overflow catch tank? IF yes, it should draw some back to radiator as it cools.

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AC 200, CAH, AC185D bareback, AC 180D bareback, D17 III, WF. D17 Blackbar grill, NF. D15 SFW. Case 1175 CAH, Bobcat 543B,

Posted By: victoryallis
Date Posted: 07 May 2023 at 8:39pm

Exhaust smell sweet?

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8030 and 8050MFWD, 7580, 3 6080's, 160, 7060, 175, heirloom D17, Deere 8760

Posted By: ssefick
Date Posted: 07 May 2023 at 8:55pm

o weird exhaust smell. No sweetness. Smells like the other equipment.

No fluid in overflow. Can see the hoses.

Tank doesn't seem to leak when I fill it. I'll check the hose a little better. Nothing obvious.

Full when I open the cap, but nothing in overflow even when I fill it after operation.

Maybe I am misunderstanding how the overflow works. I am just making sure I am not missing something.

Posted By: rw
Date Posted: 08 May 2023 at 5:36am

For the overflow and recovery system to work properly the radiator has to be full to the top for the filler neck for the pressure cap, so fill the radiator all the way with the engine cold. The cap has to have a good rubber gaskets that will seal leak free against the top of the filler neck. No dings in the top of the filler neck. The brass valve in the center of the smaller rubber seal should have some spring pressure when you lift it away seal. Check for cracks where the overflow tube solders on the side of the radiator filler neck. Fill the overflow up to the full cold.

The idea was to have system full of coolant eliminating the air chamber in the top tank to lower air entrainment in the circulating coolant that contributes to poor heat transfer, as well as cavitation/electrolysis and the progressive damage that goes with all that.

Air entering in any of those places or a leak in the overflow tank will give you an inoperative recovery system resulting in air in the top tank of the radiator when the engine has cooled.

Posted By: ssefick
Date Posted: 08 May 2023 at 6:52am

Thank you for this explanation. I will inspect this part of the coolant system.

Should I get an agco radiator cap if needed to be replaced?

Aftermarket ok? Manual has specifications?

Thanks for all of the help!!!

Posted By: Ky.Allis
Date Posted: 08 May 2023 at 10:06am

If the radiator is staying full, then I wouldn't worry about it. Older tractors or any vehicle did not have recovery tanks and worked just fine. I never had a recovery tank that worked right anyway. Usually they are always empty.