Welcome to Just Commodores, a site specifically designed for all people who share the same passion as yourself.
yes i had a similar issue , removed the radiator cap to check the water , then i noticed i was loosing water , had air in the system, now have to bleed when ever (if i do) take the cap off.Been checking the coolant level via removing the radiator cap?
Been correctly bleeding the cooling system before refitting the radiator cap?