I'm thinking about flushing the coolant on my 2014 LX 570. Is there a bleeding valve on this vehicle? Is it recommended to flush and bleed when changing coolant? I don't think this vehicle's coolant has ever been changed. It's now over 174K miles. The carfax sheet said coolant checked at 90K miles...not sure if that means flushed/changed or just simply checked if it's low or not.