In order to chase down a cooling problem I have been having, I am ready to pull the heads off my engine to inspect the water passages. Never having done this before, is there anything i need to know before hand? I will use new head gaskets and a torque wrench when putting the heads back on but is there anything unique I should know about in advance? I don't like surprises....<br /><br />On a related note, both of the thermostat housings on my engine have small rubber hoses that go to a common device in the center of the block. It looks like a check valve or something like that. Can anyone tell me what this thing is / does ? What happens if it were to malfunction? Thanks in advance for any help.<br />Jim
