Why the **** won’t my rear brakes work??

[c30]

I would have replaced the rubber hose to the axle in a heartbeat going from past experience.
I will never buy another chevy truck with the hydro boost system. Had a 2001 C30 and never did get the rear brakes working. Even took it to the local Chevy truck dealership and they could not get it to work.
This truck had the load sensing valve inline to the rear brakes. I pleaded with the dealership to just bypass the frickin thing, but they would not alter the factory system. And have you ever seen all the leakage from the hydro boost, under the hood?
Went through front brakes alot before I got rid of that POS.
Dump the hydro boost!