James Price I think your local NAPA ,Oreilly,Autozone can help you is just expensive. Had better check it over carefully may be still good,I have 2 that are about 70 yrs old work fine. In the service book they tell you to give the booster Bendix vacuum cylinder oil (2 oz.) Jim Carter himself told me that is hydraulic jack oil found at your local parts store. Done that thru a 1/8 th. plug on the booster went to working good !! Inside there is a big leather cup that likes that oil 2 times a year. Once you get it serviced it makes a special noise when it is happy. Good Luck with your service.