I was trying to order Case Hytran for my Case IH tractor. The new holland dealer says that the tractor (DX55) is the same as a TC55DA and the fluid that should go in it now it New Holland fluid. Are these two compatible or not? I am going to change my steering fluid filter and will lose most of the fluid, but there will still be Hytran in it. Can the two fluids be mixed? The parts on the two tractors are identical...same part numbers and all, so I know the fluid will work by itself, but can I mix it?