I noticed the past 2 days a wet spot under my truck. This morning the wet spot was about the size of a quarter, after sitting over night. I looked above the wet spot, and I saw a drop of antifreeze on the pan. I checked, and the antifreeze is coming off the plastic tube the UPPER radiator hose is connected to. I didn't see a hose clamp, and I'm wondering if the plastic piece is part of the lower radiator hose. It seems like it only leaks when it gets cold over night. B.T.W. , this is on a 2015 5.0L with 126K miles.

Thank you!

 

Is this the leaking connector off the degas bottle? Or the big plastic Y for the thermostat? These are two common leak areas and are a fairly simple fix.

Y issue and fix:
https://fordauthority.com/2021/06/fo...an-tech-video/

Here is some info about the Degas but you can search as well.
https://www.f150forum.com/f38/coolant-leak-489636/

 

Thank you for the information! mine looks to be the Y issue, because I can feel coolant on the bottom of the upper radiator hose plastic piece.

 

Ok glad to hear you may have pinpointed the source! I think based on FordTechMakuloco's info you may be able to get the parts needed and swap them out to address the leak?

I don't have a 5.0 so I haven't done the work myself.

 

Yes, thank you so much for your help! I've found that parts at Rockauto. From the video you posted, it doesn't look like that bad of a job.

 

I changed the upper radiator hose O-ring today, old O-ring was flattened:

 

Wow! That should most certainly help.

 

Once again, thank you for your help!

 

Did you pop in a new Motorcraft thermostat while you were replacing things?

 

I replaced the thermostat with a Motorcraft thermostat when I flushed the cooling system, and replaced the coolant with Motorcraft yellow coolant about a years ago.