Does my cooling system have an air pocket?
I recently replaced the water pump and thermostat on my '04 4.7.
When I drained the system, I collected about 2 gallons from the system. When I refilled it, it only took about 1.5 gallons. I used the air bleeder when I refilled it. I ran it with the heater on to make sure I circulated that portion, as well.
I expected the system to work some air out over the next couple of days and have to top off the reservoir, but that hasn't happened. My reservoir is actually overfilled now. When I remove the radiator cap, it appears topped off.
So, how could my system have held more fluid before? Could a bad radiator cap make it so the system can't draw fluid from the reservoir?
Amateur mechanic here... thanks for the help.