I could use some help sourcing a coolant leak

More pictures from underneath and one from top view

 

It’s definitely coming from the driver side upper area… Must be the tank?

 

When you add coolant how are you adding it? Are you filling the expansion tank or via the top of the radiator then burping the system

Can it be possible you have air in the system and its causing pressure in the expansion tank then spiting it out via the overflow hole.

 

After stopping and letting it cool down over night I added to the recovery tank when I was on my road trip. The recovery tank never fully drained, it was at the low mark and I filled to the high mark that's about the middle of the tank. The radiator fluid level in the radiator never dropped, just the reserve tank. I filled it twice that way. The new rad . has been in for about 3-4K miles and has been trouble free up to this trip. Thanks

 

I'll try running it with the cap open and the heater on and see if I can get any air out.......

 

You need to find a hill to burp it. Nose up.

 

I suspect you could have a pinhole leak or hairline crack somewhere that's slightly leaking and then the fan is blowing it around the engine bay.

 

I did the pressure test when I first got home on Weds and didn't find any leaks. I just "burped it on a hill.....got a about 8 small bubbles out, the coolant overflow tank level rose up about an inch above full when it was running without the rad. cap on and heater on high.. Used a baster and brought it back down to full line. I'll drive in the heat Sat and have my son with me so I can pull over and keep it revving after climbing some hills when it's hot I think it is coming from somewhere on the recovery tank .........that seems like it's where the drips hit the fan and make the spray pattern.. Maybe rig up a recovery tank for the recovery tank overflow port? or replace the recovery tank? Thank all for your input........

 

I never did locate it.....but I didn't really look for it. lol The truck runs at normal operating temp. I haven't had it run hot so far even in the sierra's climbing at 100 outside last weekend. I guess a new thermostat couldn't hurt. and try to find that fallen "button".

 

Put a ballon on the reservoir tank relief end see if it ends up with coolant in it. Might be a dumb idea but I would try it

 

I did a test run yesterday afternoon about 85° weather, 45 minute drive up some big hills, revving it and running the AC to put some stress on it. No drippage.

So the new radiator cap along with burping to get all the air out, tentatively solved the issue.

I did rig up a small overflow tank on the overflow tank and no fluid in there at all. Thank you everyone for the input . I’ll post an update, if things change, but so far so good!

 

You may have a small coolant leak in the core of your radiator. It is quite hard to detect, I would loosen your shroud so you can see the back of the radiator itself and blow on it with something that moves a lot of air like a leaf blower or something with good velocity and volume.

I spent a lot of time looking for a coolant leak that would coat the inside of my engine bay; with most of the deposits around the radiator cap.

It ended up being a pinhole on a newer radiator about 3 inches below the cap, it would only present itself after I drove around for a while; as the droplets carried by airflow of driving would hit the fan, and be spread around the engine bay by the spinning fan.

Have someone blow into the front of your radiator with leaf blower while someone checks out the back of your radiator with the shroud off!