head gasket

[Toms306]

Why? The water pump pushes water through the pipes so how can the air get trapped? Keep the cap off and the level topped up obviously and watch the bleed valve until it runs clear then close it as normal... Its the highest point so where else will any air get trapped? You can't do it like that with the bleed valve closed obviously but I really don't see how there's a problem doing it the way I did.