Hey guys, well finally got my header tank installed yesterday, was a piece of piss. All I did was disconnect the big hose and drain the plastic tank into a ice cream container so I didn't get water all over the place. Then removed the plastic one and bolted the alloy one in its place. Connected all the hoses backup and filled it back up with water, ran the car for for a bit while it was at operating temperature with the cap off. Now on the way to work this morning I was thinking I didn't leave it idleing long enough as the water didnt flow out the cap of the header tank. I wouldn't imagine what I have done would cause a air lock in the system but how long should it be left at idle to get rid of air locks? Not to sure about bleeding the system on these cars, as my old had a bleed valve on the front of the head that let the air out. Car drove perfectly this morning, was just a paranoid thought I had on the way to work. any input would be appreciated thanks guys.