ATF coming out of vent tube

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Italianwagon

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Ok so drove the burban around and crawled underneath later noticing atf fluid everywhere. Any ideas why? Looks to have come from the vent tube

just recently replaced radiator with new internal trans cooler, thermostat And rest of the cooling system.

Excess fluid being pushed out or moisture being burnt off? This from the new radiator and internal tranny cooler?

attached photos are of the vent tube and just to confirm that’s a th400 right?
 

Italianwagon

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Sorry here’s the photos

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QBuff02

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The only time I've ever had fluid push out the vent tube on a th400 is when the trans was overfull. Did you add some fluid back to it after you changed components? If so you might not have lost as much as you thought and it's just pushing a little out. Do you have rubber lines inline with the metal going to new cooler? Possibly check for a kink or a restriction in one of the lines if nothing else has changed.
 

Bextreme04

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A plugged cooler will also cause it to shoot out like that. Did it drive ok? Definitely check the fluid level. There was a roadkill episode where they had a clogged external trans cooler and it was plugged up solid, every time they started it, the trans fluid would flow out of the dipstick tube from the restriction. If you just had the trans cooler replaced in the radiator, check for kinks and restrictions.
 

Italianwagon

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Fluid was full and not burnt. Drove fine all day. Checked the transcooler. Didn’t see any obstructions and seemed to be flowing fine
 

Rhett Croley

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Is it coming out of the transmission vent or the t-case vent. If it's the t-case then transfer case-transmission seal is blown and pumping transmission fluid back into the transfer case and it's running out of the vent tube?
 

ballencd

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I concur with last post. The transmission pumps fluid into the transmission to transfer case adapter, apparently to lube the speedo gears and drains back into the transmission. IF the transfer case front seal is gone it gets pushed into the transfer case and forced out the vent on top. I had this happen to my 91 V1500 awhile back. Quick fix with the front seal. When I pulled my transfer case it appeared dry but idling it with the transfer case off, it will squirt fluid into the empty adapter.
 

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