I have an 06 H3 with 51K miles and auto transmission. My radiator was leaking between the top plastic tank and the aluminum core in the corner nearest the air box. My leak rate was about one drop every 2 seconds.

I removed the upper hose from the radiator, removed the fan shroud, removed the upper rad bracket, and unbolted the radiator from the AC. I was able to lift and move the radiator front and back so I could use channel locks to re-compressed each tab that holds the top plastic tank to the aluminum radiator. No more leak for now. So far no signs of any weeping.

I used two pipe extenders on the channel lock handles to be able to apply more force. I re-compressed each tab twice. Your forearms will be sore.

I'm guessing there is a gasket between the rim of the plastic tank and the radiator core that serves as a seal and the force of the tabs are suppose to keep the seal compressed.

I'm going to drive it for a few days and see how this holds up. If I see any weeping I may use a tube of bar's leak to see if this cures the weeping.

This took about two hours to complete.

I'll keep this thread updated with the good or bad.

 

I hope that fixes it for you. I thought that is what mine was doing too. It took a while for that hairline crack that all of us are getting to actually appear so that I could see it. On mine I never did actually see a leak for around 6 months. I would just smell coolant from time to time and could see where it was blowing on the engine every now and then. It didn't even lean on my driveway. Keep us posted and let us know how it goes...

 

Just an update. After a few trips I saw little puffs of steam - no fluid just steam. I tried some Bar's leak and it worked for a few more trips. Then I saw a couple more puffs of steam.

I ordered a new radiator.

I installed a tranny cooler and bypassed the one in the radiator. Here is a picture.