miele 4070 clogs after two cups?

My Miele 4070 clogs after two cups if I do not do a system rinse after cup. I do a clean cycle twice every Friday, this does not help. I have had maintenance on it twice at $150 a pop and the problem is a small hole at the top of the brew unit about the size of half a pencil eraser that clogs with fine grounds. How can I keep this hole from clogging all the time. The service tech was great and taught me how to take apart the top of the brew unit. I can'f find the needed torx T14 to do the job. It takes a T 14 and T15 to do this. Why should I need to take the unit apart? Is there anything I can do to help prevent this? The techs only idea was to run the clean cycle more. Help