Infamous bubbles or troublesome radiator try this.

[phix-]

Through the many years of owning explorers I have noticed something yesterday that quite possibly still has me in awe. If you have ever turned on your truck to find your radiator was leaking water and appears as if it was cracked along side the plastic/composite tank where the radiator cap is located. Try tightening the washer that mates with the transmission upper hookup is located. With it being colder than it is most of the year recently I found out that this was causing a leak only at startup and under pressure it was spraying some of the pulleys with water. I am not saying this will fix the issue you may have (as cracking the the tanks can be accomplished). Just saying for you colder weather guys, I have noticed my upper hose still leaks till it warms up.

 

[yavapaires]

Through the many years of owning explorers I have noticed something yesterday that quite possibly still has me in awe. If you have ever turned on your truck to find your radiator was leaking water and appears as if it was cracked along side the plastic/composite tank where the radiator cap is located. Try tightening the washer that mates with the transmission upper hookup is located. With it being colder than it is most of the year recently I found out that this was causing a leak only at startup and under pressure it was spraying some of the pulleys with water. I am not saying this will fix the issue you may have (as cracking the the tanks can be accomplished). Just saying for you colder weather guys, I have noticed my upper hose still leaks till it warms up.

Yes, cold water leaks are more common than most people think. This one reason for silicone hoses and spring loaded clamps, especially on big trucks. Same works on private vehicles too.