Gordon, the latest bus wipers are computer operated! ***ing usless but computer operated! They have at least uprated the wiper arms. The old ones were held together by pop rivets and had a habit of shearing and banging on the roof of the car in front. The idea of a vacum resovoir appeals, though possibly 6 volt electric would be the real answer. Trouble is everything else is dates to at least the 1952 rebuild, and it all works! Though I do know some sad souls who restore buses (!) so I'll ask them. Got to think ahead now the Grandaughter could be heading for D-Day 100!