Whats the proper way to bleed the coolant lines for an 84 300SD. I have just acquired an 84 300 SD and have put in a new thermostat. I turn the car off when the temperature gauge is just shy of the mark between the
80C and 120C (I assume this is 100C). There is also no heat out of the heater where there was once before. So I probably still have air in my coolant lines. What is the proper way to bleed the coolant lines? As an aside question, is there a way to tell if there is air in the coolant line versus the thermostat being bad?