Originally posted by Thomaspin
If you want to use this on earlier (pre-1986 I would guess) cars that do not have the auxiliary vaccum pump, you will have to deal with the additional complication of lock actuators.
Don't all W126 sedans have a vacuum pump? My 81 SD has a vacuum pump in the trunk just like my 91 SE. Maybe only the pre-86 Diesels have a vacuum pump.