Quote Originally Posted by chopper View Post
You also need a double sealed " recovery style " radiator cap for the coolant to be able to be drawn back into the radiator. A 600ml plastic coke bottle with a hose going down through the cap to the bottom of the bottle and a small breather hole drilled in the cap beside the hose does the job also.
I used to use a 1.25 litre Coke bottle.