yep, my dad's drivers used to moan the lorries were always using coolant (the expensive water free stuff so not good). then i found them in the morning filling the header tank til it spilled out the top. i bollocked them 'cos i'm sympathetic to stupidity like that and told them to leave the level at the bottom of the neck (about 4-5 inches down from the top). strangely they all stopped using coolant