I don't remember any. The expansion tank is the high point in the system. Fill it up then run it; let it cool and top it off at the expansion tank and add to the overflow bottle. I mark my overflow bottles both cold and hot so I always know what is going on with the system.So we took it out to load test it. I found 3 coolant leaks in a section our now fired mechanic replaced the housing regulator that be busted the flange off of and the hoses should've been replaced. Got new hoses now.
Is there a bleeder valve somewhere on the coolant circuit?