Hi - 2007 H3, Base, AT. Radiator leak where the plastic tank mates to the aluminum just to right of the upper rad hose. Constant stream when truck is running. Have a new rad coming early next week. I live in a small town in northern AZ - so shipping
always takes an extra day or so.
In trouble shooting with the truck running, it heats up to 3/4 pretty quickly & boils/bubbles? I had to top it off with distilled water to get it home so I'm sure the Dex is all but diluted. Already did an exhaust gas test - all good. Could the leak be sizable enough to cause a loss of pressure to boil/bubble? Truck has not been overheated. Has a new water pump as of 4 months ago. I don't think the thermostat has been replaced since 2010 from the service notes I keep in the owners manual. Just trying to plan for additional parts orders that come on the slow boat to our neck of the woods. Thank you.

 

Yes, do some research here. There are some good u tube videos showing best methods for changing radiiator.

Allow about 4 hours for the task.

 

Great, thank you. Watched several YouTube videos & it doesn't seem like a terrible job. The boil/bubblinh just worried me.

 

Check for a combustion leak>>>

Combustion Leak Test Kit - Made in USA

Combustion Leak Test Kit - Made in USA

 

That was the 1st thing we did -all good. New rad gets here Saturday. Took the rad cap off last night to only to have the o-ring come off in pieces. So between the plastic tank leak & a bad cap, I think the problem is pegged. I'll report back this weekend once the rad is replaced.

 

The cooling system relies on keeping the coolant under pressure. So, any leak in the system, from the cap or the crack in the radiator, will allow it to overheat.