I read several post about coolant issues. please help.

Looks like it's on a 14l 60 series Detroit, I'm not sure what's it's called, but on those engines when the put pressure into the surge tank it's usually the head gasket. You can take a water bottle with some water in it and stick thebover flow tude in it and if it make bubbles with the truck running there's a problem. Or take an empty one a zip tie it to something and stick the overflow tube in it while you drive and if there is coolant in it after a drive( if the tube doesn't blow out) that usually means there pressure in the system and usually that's from the hea gasket.

 

Compressor head gaskets can also fail and put air into coolant

 

What did your problem end up being ??

 

Could also be air compressor if it's water cooled. Can't bad injector cups cause aeration in the coolant as well?

 

Injector cups will usually put fuel in the coolant.

 

yup had a old Box truck that had sat for most of the year and the cups went bad .