GM/Delco Hy-power brake booster
 

Could anyone help me out on which brake port goes where? Forgot to take a look when I pulled this unit.

Also if you have a wiring diagram for what sets off the electric motor, that would be very helpful. I'm guessing its very similar to the hydromax units... In that:

#1. ign off, brake pressed - electric motor runs
#2. ign on, power steering no flow - electric motor runs
#3. ign on, brake fluid no pressure - electric motor runs

https://imgur.com/a/BvCQb9w

https://i.imgur.com/B6z57jIl.jpg

Re: GM/Delco Hy-power brake booster
 

I remember those systems, but never worked on them much. Your best bet would be to pick up an original GM service manual for your truck. Usually not too expensive on Ebay. Always useful to have when you own an old truck.

Re: GM/Delco Hy-power brake booster
 

Here you go. If the pictures are not readable let me know and I'll redo them.

-Richard

Re: GM/Delco Hy-power brake booster
 

thanks rkn463!