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Q: I replaced the heater core and it isn't blowing out really hot air, also, it has a bad radiator cap.

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Should I bleed my radiator? And can changing my heater core cause air to be in the system?

My car has 243282 miles.
My car has an automatic transmission.

The answer is yes, you should always bleed the system when completing cooling system repairs to ensure that all of the air is removed. Air can be trapped in the heater core and will cause the heat to not work efficiently. If you need help with this procedure, a certified technician, like one from YourMechanic, will be able to bleed the system for you.

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