Radiator coolant level

[Cummins593500]

Is the radiator in a 3rd gen 5.9 supposed to be filled to the brim when the engine is cold? the expansion tank is full and I just bled all the air out of the system using a coolant funnel kit. Took it for drive then checked the radiator after it cooled down it was about 1 to 2 inches below the filler neck is that normal for these trucks?

no leaks on the ground and no milky cap or dipstick

Heater core is bypassed

Should also mention it’s a new radiator truck heater exchanger had failed and transmission fluid mixed with coolant. Radiator, transmission and heater exchanger was replaced

 

[Motorpirate]

Sounds like a radiator cap not letting the coolant suck back in as it cools off.

 

[jws123]

Sounds like a radiator cap not letting the coolant suck back in as it cools off.

exactly this replace your rad cap and make sure your overflow is not clogged.

 

[Cummins593500]

So the radiator cap was bad I replaced it and it is sucking back from the overflow tank had to bleed it again but radiator is staying full now