K Todd I realize bars leak can cause problems if not used properly. The problem is still little heat the heater core lines are, to quote my son, "pi$$" hot in and out. This is under the hood and under the dash. The radiator is new, Thermostat new, and the coolant is clean as a whistle. I checked the heat cool mix door the actuator is moving and you can hear the door operate. Oh I only used half strength on the bars leak.