Been having problem with building pressure in cooling system
I've run out of idea's on this problem I need some different views on this problem. I have a 2006 Detroit Series 60 that builds pressure now and then the pressure is not steady one time it will be normal you might drive 500 miles or so everything is fine next time you might drive 50 miles and building pressure and it doesn't last very long. It has no combustion gases in antifreeze has no by products of antifreeze in the oil sample. Oil sample comes back normal. This trucks heater system does not use air to operator it so there no air supply to the heating system at all.
Is this a good question?