No, that's not the case. The cooler that sits in the bottom of the radiator is aluminium and is only held in place by the nuts on the front of the radiator. I've posted photos somewhere on the forum of the one I dismantled, it clearly shows corrosion being the problem. I would say another way of preventing this would be to dismantle one side of the radiator connections at a time, clean well and replace the O rings, that should do the job....if you're brave enough!! I have also fitted a separate cooler, also a very very easy job.