There may not be a "one stop solution" I have an 82 300D and it was plagued with a number of leaks when I bought it. None of the leaks on mine were serious enough to cause the fuel shut off system to fail or to make any one component fail completely. My series of leaks caused random and intermittent component partial functions. Due to the amounts of vacuum lost there was not enough residual vacuum to allow the component to function completely or punctually. I have not found all my leaks yet but as I find and correct leaks the "system" works better and more consistantly. The following thread may assist you if you have not seen it.
82 300TD A/C problem