Ok basically... I work at advance and im only so familiar with these things. Customer has a 76. 3/4 ton... cab and chassis... doesn't run the ps pump that would typically be on a 76 (press on pully) it uses the cone shaped ps shaft that has a nut that holds the pully on. So I ordered him one off a 60's nova... which fit great... customer has installed the pump and now when u turn the truck on the brake pedal goes to the floor and the brakes are activated... its not loosing hydraulic pressure... ts like the hydronoost is pushing the breaks on its own... im not sure what the problem is... but that style of pump pre-dates hydroboost... im just trying to find a solution over selling him a newer style pump, then telling him to find a pully... as im not sure why his trucks power steering pump has a single return line while the one my computer says fits it has 2... anyone more familiar?

 

sounds like he has the brake pressure hose and the PS pressure hose swapped