I took my car in today. They said it is losing 4 lbs of vacuum pressure when they turn on the A/C. Which is causing the brakes not to work. He said the loss of vacuum pressure could be caused by the whole in my resonater and the valve cover was loose some oil was leaking and leaked in the spark plugs. I am going to just replace the resonater with a pipe and I tightened the valve cover about a year ago because it was loose and leaked some oil and I guess it needed to be tightened again. Any thoughts on the vacuum issue or how to keep the valve cover tight. They wanted $275 bucks to put a new valve cover gasket,plugs and wires. I am going to do it myself for a lot less.