Still have problem w/ no heat and leaking coolant.

[Beav]

Yes, but the air comes in through the surge vent in the radiator cap.

[cbx-man]

Originally posted by Beav
The pressure generated by heating the water in a closed environment precludes the water pump being able to allow air into the cooling system. Water leaks out, air doesn't leak in.

Hope this doesn't get ugly

Beav, I agree with you 100% when the system is pressurized. But the system isn't pressurized 24/7. And when the system leaks , by definition, it is no longer a "closed environment".

My point is that the weep hole on the water pump is higher than the thermostat, so the air entering the system has to rise. Into the motor. Which eventally settles in the heater core somehow. No hot water in the heater core, no hot air from the heater.