I recently bought a secondhand tanker that had been layed up for quite a while. It had only been used for water. The guy had said the pump maybe seized. I don't know much about tankers but thehe change over on top is moving no problem but I can't turn the shaft with a bar and I'm afraid to put it on the tractor in case it wrecks it. What's the best thing to do? Strip it down? Or try the tractor?