1983 300TD wagon Vacuum Issue: on my 300TD wagon the vacuum leaks down (15 minutes) after shutting down the engine. Upon starting the engine it takes about 1 minute for all the door locks (including the rear hatch) to open. The engine shuts off properly and no problem with the power brakes. The other issue is that I need to let the engine run for about 1 minute before the center AC pod will work allowing cold air to come through the the middle vents.

Is this a vacuum reservoir issue or ? Thanks.