No evidence of rubbing on back cover, it just gets pushed out and dumps the coolant. The pumps have been replaced under warranty.

I assumed at this point that i have a possible warped head and compression or exhaust gases are pressurizing the system. It started out just overflowing the tank. As I kept checking different thinks and running the truck again it got progressively worse. That's when it blew the back from the pump. I thought the first was a fluke so tried again, same result. I flushed the radiator to ensure no blockage and blew the pump again.

So, other than warped head what other possibilitiesare there? I need to get the truck running again if only just to get rid of it. I don't want to buy an engine if I can repair this one.

So, any suggestions? I thought the 243 heads might have been some one trying to fix the problem or might even have been the cause of the problem.

 

Pull the heads. If it’s a HG issue it should evident.

 

The 243s are the stock heads.... lol.... they aren't some performance head somebody added on. Every damn gen iv 4.8 and 5.3 from 07 to 2013 had those or 799s. Head gaskets, pull heads!

 

Thanks guys, heads coming off as soon as it quits snowing.

Dave