2008 explorer coolant system air bound

[Drslim020]

Recently bought a 2008 explorer 4.0l v6. Seems to keep getting air in the coolant system. Heat comes and goes inside the cab. Replaced vacuum lines to heater core valve, replaced heater core valve. Replaced radiator cap. Going to replace thermostat and housing tomorrow. Any other advice on what could keep allowing air into the system? When I replaced the rad cap yesterday, heat worked great. Until the next morning, when the system went air bound again. Thanks in advance

 

[BCosta]

Recently bought a 2008 explorer 4.0l v6. Seems to keep getting air in the coolant system. Heat comes and goes inside the cab. Replaced vacuum lines to heater core valve, replaced heater core valve. Replaced radiator cap. Going to replace thermostat and housing tomorrow. Any other advice on what could keep allowing air into the system? When I replaced the rad cap yesterday, heat worked great. Until the next morning, when the system went air bound again. Thanks in advanc

 

[BCosta]

Get yourself a coolant funnel kit.
Amazon or Ebay, i think they're under 20 bucks.
I just recently changed the heater hose, lucky to have broken down near parts store, and in a rush, i was back on the road under 15 minutes, BUT I forgot to completely purge the air out. Couldn't drive ¼ mile without guage going red. Got it home, & once i used the kit, everything good.