Duramax Fifth Generation: 2011-2016 (LML)
Like the tittle says :16 LML coolant do not go back to pressurized side when cool off.
the coolant stand in the middle
Of the pressurized side and do not pull back what is in the overflow when cool off. Top rad hose is soft in the morning, new thermostat and new coolant tank . ( weird is when I...