Why not just remove it too? It does not take long to do and it will save you frustration. You will be loosing a lot of coolant when you change out the pump, why not drain the radiator too, flush and fill up with new Zerex?

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine