This coolant system is really starting to get on my last nerve. So far I have replaced the thermostat( tested before install and worked fine), coolant, filter, heater blower motor, rebuilt the actuator, flushed it, block heater twice,temp sensor twice and replaced upper rad hose twice. So I drove it into town today and guess what? Yep it overheated! Then the actuator didn't work, Of course. So I bolted the fan and that was of no help what soever. I was hoping to enter into the Memorial day parade, but now I'm really thinking of driving it off a cliff!!! When I got the truck home air was bleeding off out of the aluminum end on the actuator valve. What is causing that? My only other thought is to drain the fluid yet again, yank the thermostat and install a new water pump. Don't really want to do that! Any suggestions on what might be the problem? Oh, I did bleed air out of the system from the heater core relieve valve. IS there another place/better place to do this from? Thanks for any and all advice!