I have taken off the top hose to measure the radiator inlet spigot. Car Builder Solutions sell an aluminium section for 32mm hose that has a bose to carry a fan sensor. By installing one I could read the temperature nearer the head. When I came to replace the coolant I couldn't get almost half of it back in. From where should the system be filled, the header tank which seems below the top hose or the radiator. After years of old cars I am at a loss.
