The only hard part about removing the vacuum pump is having the proper wrenches and room to swing them, but access is probably easier on a 70's 240D. The 6 mounting bolts are allen head (5 or 6 mm I recall). Best to have a 3/8" drive allen socket, though you still need a hex wrench for a few. Last time, I unbolted the p.s. pump for better view and access, but mainly because I had its belt off for other front-end work, plus I wanted to clear spray my now cleaned up front.

The vacuum tube (probably 2 on yours) needs a big wrench (at least 19 mm I recall), plus a backup wrench. Some adjustable wrenches would work.

Of course, measure the vaccum and decide if the pump is the culprit first. Any leaks can over-whelm the pump, so before condemning it, connect just the gage to the pump's tube (inlet).

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1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans