As already discussed here, an electrical vacuum pump is required to power the brake booster.
The pump is a used part, but in good condition.
The pump is controlled by a vacuum switch and the vacuum pump driver. This is also shown in the general wiring diagram.
The mounting bracket consists of a base that is bolted to the battery box auxiliary frame, and a top part that holds the pump.
Mounted pump. It is essential to suspend the pump in very soft bearings. Otherwise, it will be terribly noisy. I have also put some butyl rubber dampening mats on pump and bracket to further silence it, and slightly throttled it's spin by a series resistor.