car overheated badly.  Runs well after, so I am suspicious thta problem
may not be a blown gasket caused by overheat. Would like to methodically
troubleshoot.  

First, I installed new water pump and thermostat. DAdded new coolant
making sure that it got into the radiator and rest of system.  But upon 15
minutes max of driving when the car comes up to temperature, it does not
overheat but all the water is gone from the reservoir.

Coul I have an air blockagelike in the heater core?  How would I ensure
that I add cooant to the system correctly?  The waht do I investigate
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pdc