I have my radiator/hose minor leak after replacing my 530 block in Vancouver Auto , May . Of course , spent more than 3500$ for the extra parts , almost everything , of couse all hoses . However I found that leak problem righ after picking up the car back and BMW dealer just told me it's my radiator problem ( that item was inspected ok not recommended to change while changing block ) and they will not fix it free , so I went to another dealer , told the same radiator thing , no way only spent big money can cure it . Becos it's not big leak ( 1-2 drop / per week ) so I just ignore it until last week it become big drop then I have to check myself and found it's a loose hose connection due to the poor tight & wrong position ( too far from the radiator connetion ) , I then loose the hose and replug & tighten it in my own way , now the problem gone !!