I have a 2012 All American with the Cummins engine. This morning the driver came in with her heaters not working and bus was overheating. I thought air in the system from sitting. Ran bus and same thing so I opened the bleeder and got steam. That's all I got after a couple hours with it.Coolant level never dropped but never could get coolant to come out of the bleeder above the thermostat. Could I have a bad EGR cooler? It acts like the block is empty with nothing but steam?
sounds like a no flow situation, bad pump, thermostat or collapsed rad, i've only seen a lose of coolant or white smoke( with dpf unhooked) due to a leaking egr cooler, some investigation would be needed
OEM trained in wiring and all engine platforms for over 20 years