Any of the above should work, especially on older machines. However, keep in mind that fluids for hydraulic systems are designed specifically for that purpose. They don't tend to foam up create bubbles), as oppose to engine oil, which may turn into a foam bath coming out of the hydr. fluid tank. I would contact a local dealer and see what is recommended for a particular model. Otherwise stick to some hydraulic fluid available at any automotive or heavy machinery parts supply.
