What is wrong if my car shakes when i press the break pedal?

This is probably the cause, it goes from the Throtle body to the top of teh valve cover. For a short term fix you can close the hole with some RTV (ruber) or some duct tape, but you should get it replaced by either buying a new hose from the dealer, or finding some bulk ruber hose and cutting it to the right dimentions.