I didn't have a problem with the plastic radiator on my old 300E until I had the cooling system flushed, then the top radiator neck broke off. I think it broke because the top radiator hose was over tightened. My new clk430 is now due for a cooling system flush. If I take it in to the dealer to have the work done, does the Mercedes recommended procedure involve removing any of the radiator hoses so they can be over tightened and the radiator neck broken off again? Or, is there a Mercedes recommended way the system can be flushed without removing the hoses?