[attachment=0:1gfsci4v]Capture.JPG[/attachment:1gfsci4v] I wouldn't call it a bleed screw. When I did my head gasket as i filled the system I squeezed the rad hose (suggested by another member here). I let it run with no rad cap untill the thermostat opened and purged the air, topped it up, put the cap back on, ran it again and then checked the level.