i need to flush coolant on the barge, when I changed thermostat so much crap came out, I didnt clean it cos I didnt have time, but it is on my to do list.
Drained it today, went to refil it with some g12++ (no idea what was in there before), and only put in about 3l before it was totally full. I don't think I may have got all the old coolant out. How bad is this? And for next time,should I run the car after I drained it to get the last bits out?