Boil over from the expansion tank?

Daughter said it is leaking antifreeze by the right tire, found that it was just the boil over from the expansion tank. Checked for external leaks, found slight drip starting from the water pump weep hole. During replacement of water pump found one bolt stripped on thermostat cover to water outlet. Installed new water outlet with new thermostat. Installed new lower hose on water pump housing due to deterioration. Checked oil for any internal leaks, oil good, no milky color usually associated with antifreeze/water in oil. Checked radiator, found A/C condenser pushed back into radiator and auxiliary cooler pushed into A/C condenser due to vehicle with trailer hitch backing into it. Installed new aux cooler, A/C condenser and radiator with new upper, lower hoses and new radiator cap. Inspected fan assemblies, both good, no broken blades and operating normally. Serviced with 50/50 mix and drove around for approximately forty five minutes before it started to overheat again which is about thirty minutes longer than when it would originally overheat. Let cool down, drained radiator and serviced with cleaner and distilled water. Operated vehicle, drained and flushed system approximately three separate times until removal of all cleaning solution. Serviced with 50/50 mix and topped off system while running. Drove around for approximately sixty five minutes before starting to overheat again. Drained system again, and found 50/50 mix very clean with no discoloration. Did not see any other hoses that required changing. The heater has been working good but wondering if there is a slight restriction in heater core allowing it to operate but also causing the overheat. Any suggestions? Ruled out a temperature sensor since it does boil over into the expansion tank and then overboard. This is just one of several problems I am trying to fix on the vehicle since moving my daughter from Michigan to North Carolina. I also have a check engine light again (oxygen sensor now), an airbag code 36 (drivers side airbag) and a intermittent brake light (left rear wheel cylinder is leaking).