when this 67 showed up here I checked all of the fluids and toped them were needed. the car sounds and acts like it has a vacuum leak so we have been changing hoses and tighting things up. discovered that today the master cylinder is dry both sides with no visible leaks under the car or on any wheel. we have about 40 miles on it now. it was stopping all right with out any brake fade and the peddle held firm. the question is do I need to change the booster and the master cylinder or just the booster?