Figure 7: 2008 Toyota Prius preheat components. Engine cooling system bleeding It has been mentioned by many, numerous times in this publication. To avoid problems when refilling a Hybrid/EV cooling system, ALWAYS USE AN " AIRLIFT " TYPE TOOL. But sometimes...! Up here in the North, cooling system service is a staple. Whether a routine drain and fill, a leak reMarch 2022 6 pair caused by corrosion or accident or major engine repair, technicians are having trouble getting the air out. Heat is important here, and a customer who picks up a freshly repaired vehicle with poor or no heat is not going to be happy. OR...you as a technician can become unhappy and grumpy having to take more time to purge air after a repair or worse, a comeback. MACS Service Reports Mitchell Pro-Demand