Originally Posted by JimPghPA
My understanding is that one of the big things that degrades fluids is exposure to air, and the very small amount of moisture that condenses out of the air and into the fluid. Over time that can add up to a lot of oxidation and moisture. When you have a dip-stick every time you go up or down a mountain, or the barometric pressure changes a small amount of air moves in or out of the air space above the fluid in your trany. When it moves in it carries new oxygen and water molecules (moisture). Some of that interacts. A sealed system does not have the fluid degrade anywhere near as fast. I have seen some engineering specifications for some fluids and there useful life that specified different life expectancy for use in sealed and unsealed systems.
Only this is NOT a sealed system, there is a vent hole to allow for expulsion of air during fluid expansion, so once the fluid constricts (cooling) air is sucked in. If for sealed you mean sealed from the owner, then that it is.
My understanding is that one of the big things that degrades fluids is exposure to air, and the very small amount of moisture that condenses out of the air and into the fluid. Over time that can add up to a lot of oxidation and moisture. When you have a dip-stick every time you go up or down a mountain, or the barometric pressure changes a small amount of air moves in or out of the air space above the fluid in your trany. When it moves in it carries new oxygen and water molecules (moisture). Some of that interacts. A sealed system does not have the fluid degrade anywhere near as fast. I have seen some engineering specifications for some fluids and there useful life that specified different life expectancy for use in sealed and unsealed systems.
Only this is NOT a sealed system, there is a vent hole to allow for expulsion of air during fluid expansion, so once the fluid constricts (cooling) air is sucked in. If for sealed you mean sealed from the owner, then that it is.