Changed thermostat on XLT 2001 and now the truck is leaking like crazy at the bottom.

[newaroundhere]

Looking underneath the bottom, it looks like all of the coolant is coming from the weep hole? I'm looking at the thermostat housing and I don't see any leaks but I'm only looking at the top of it. It looks dry. I do know that the day I changed the thermostat, the crack between the bottom and the top of the thermostat housing had water coming through it so I had to adjust the tightness of the screws and it's been dry since, but the next day when I try starting it up at about 15° Fahrenheit weather, it sounded like the belt was squealing while driving and then later that night when I got in he truck, I see a huge puddle underneath the truck, so that's what I look underneath and it's leaking all over the place over everything.

My question is, is it most likely the thermostat housing or the water pump? There isn't any overheating and the heat works

 

[oklagp1200r]

Looking underneath the bottom, it looks like all of the coolant is coming from the weep hole? I'm looking at the thermostat housing and I don't see any leaks but I'm only looking at the top of it. It looks dry. I do know that the day I changed the thermostat, the crack between the bottom and the top of the thermostat housing had water coming through it so I had to adjust the tightness of the screws and it's been dry since, but the next day when I try starting it up at about 15° Fahrenheit weather, it sounded like the belt was squealing while driving and then later that night when I got in he truck, I see a huge puddle underneath the truck, so that's what I look underneath and it's leaking all over the place over everything.

My question is, is it most likely the thermostat housing or the water pump? There isn't any overheating and the heat works

Go to auto parts store or a mechanic and have them pressure test the system for leaks.

 

[amj441]

When I did my thermostat, I found out that the lip of the neck where it meets the thermostat had disintegrated and blew out. This was required to push the oring and seal the thermostat. I had to replace the thermostat housing outlet to fix it. Id recommend going with a dorman metal housing and replace the entire housing.

 

[410Fortune]

You should have replaced the entire housing. It just the thermostat

They crack
The aftermarket makes a all aluminum housing because of this

 

[wollimann]

No leaks again, best housing ever.

SimmonsAutosportz

Auto parts, thermostat housing, metal thermostat housing, ford 4.0 aluminum cast thermostat housing, one piece thermostat housing. 2005-2010 mustang metal thermostat housing. explorer metal thermostat housing, ranger metal thermostat housing, sport trac metal thermostat cast housing. metal...

simmonsautosportz.com

 

[oklagp1200r]

No leaks again, best housing ever.

SimmonsAutosportz

Auto parts, thermostat housing, metal thermostat housing, ford 4.0 aluminum cast thermostat housing, one piece thermostat housing. 2005-2010 mustang metal thermostat housing. explorer metal thermostat housing, ranger metal thermostat housing, sport trac metal thermostat cast housing. metal...

simmonsautosportz.com

That's the one I installed over 10 years ago I believe and to this day no issues!

 

[olddaddy75]

Does the same happen to the 4.6 V8?

 

[410Fortune]

No
Flashlight and coolant pressure tester is how you find coolant leaks

Sometimes if it’s a real mess you can power wash or spray down the area with brake clean and baby powder can then help find the wetness

For very difficult to find coolant leaks they sell a uv dye and light .. with the baby poweder trick and lots of light I have never needed it