Hello, My Powermac G5 Dual 2.5 Ghz was operating on temperatures like 75 Celsius degrees, witch I think is high. So I decide to clean the dust off from the computer. When I open the processor decorative case I found a corrosions marks, it was a leak from the liquid cooling system (LCS) . I sent my mac to the assistence, they said I need to replace the processors and the liquid cooling system, that is very expensive - very. So I decide to fix the leak by myself (because my G5 is working and I do not have enough money to fix it on the correct way).The LCS´s tubes and metals are fine, I don´t have pictures of it right now (my computer still on the repair service), but you can have an idea from the LCS by this diagram (http://www.appleinsider.com/article.php?id=508). The leak is under the liquid pump (that´s made of plastic, looks like an aquarium pump). It´s a little leak(Maybe this is happining due to a failure on the rubber thats seals the pump on the metal) . Im thinking to use a high temperature rescistence sillicone to seal the leak, maybe an rubber ring too or epoxi. I know that the G5 LCS was not made to be opened, but I think I should complete the liquid (the liquid is Delphi 151 but I think any other liquid for LCS should work). I think that will be no big deal the fix the leak, but i´m worred about all the liquid that was gone (for what i saw this liquid is coming out from under the pump for almost a year). I don´t know for sure how this liquid cooling system works, so I don´t know if the liquid works with or without air, with air can enter the pump, or something like it. As I said I thinking to replace the current liquid to a new one ( I think that is can be made by simply opening the radiator cap). Sorry my english, im from Brazil.