Yahoo Message Number: 9252 (http://groups.yahoo.com/neo/groups/supercrvgroup/conversations/messages/9252)
As you have seen me post I am on the 3rd radiator in about 10,000 miles.
Well even though GMC is out of the mid-duty truck business, they have done the right thing. I was not incorrect when I thought the radiator was a complete piece of shit in engineering, material, workmanship and quality control. They have such a high failure rate that it has been re-designed and now has a superseded or service filed replacement part. If you get yours changed out, make sure you get one from Michigan and not out of local inventory.
If you do also have a failure I would recommend running the test on the coolant to look for traces of exhaust in it: early failure would happen to the head gasket during high turbo boost. More than likely you might get bypass fluid into the overflow [ but your radiator cap may have also failed so the excess pressure would blow out the radiator (seals.) Just something to look out for plus its cheap / easy to test.
Be well and travel safe!
Victor
2008 Kodiak Diesel Dutchmen 34H
SoCal Baby!