I am replacing some split hoses at a T beside the Master Cylinder from which one hose goes to the cruise bellows, one goes somewhere down under the jack, and one goes through the firewall. The bellows hose holds vacuum and the bellows pulls in if I put a mitivac on it, but the hose through the firewall, which I believe goes to a vacuum switch on the brake linkage, does not. Should the hose to the vacuum switch hold vacuum with the engine off?

 

the hose under the jack goes to the well hidden vac pump under the jack-behind the headlight...you can move the pump up on top where it'd be easier to get at.....I dont remember about the foot pedal switch....but I'll check mine tomorrow

 

The hose that runs down under the jack ends at the vacuum pump.

Good luck with getting your cruise control working. I've found that most of the old Hella cruise control ecu's are long past their sell date. If, once you get your vacuum hoses sorted, you still don't have cruise control, pull the ecu and check the circuit board. You'll probably find a few bad solder joints. An awful lot of people who really want cruise control in their DI's and GEMS P38's have been buying the later Hella ecu that was found in the DII. A quick search will turn up the information you'll need for the conversion.