Hi, I have a vortech fmu, but it doesn't seem to work properly. I opened it up and there are two circle rubber gaskets in it. One is larger than the other. On both gakets there is a crack in the middle, but I do not know if it's suppose to be like that or does it need to be sealed completely. (without any cracks). Is there somebody outhere that knows if the gasket must have a crack in it or it suppose to be sealed completely?? Let me know!! Thanks!!