I don't exactly know what is going on with this thing. I bled the brakes out a few different times and I still have to push the pedal through the floor after pumping it to slow the damn thing down. I also can't find anything about the brake system on this thing. Has anyone here owned on of this year, and is it common to have two brake lines on both sides of the front end? It was a factory built delivery truck for a brake shoe company ( ironic, I know). I've replaced the booster and thoroughly inspected all of the lines twice. There isn't a lspv on the rear axle either. It also has a 20R out of an 81' rigged in it too. Also I could use a few pics of the 20R vacuum lines that run to the driver's side. I really need an adult on this one!

 

are you getting vaccume to the booster?
honestly im not familliar with this truck,but brake booster's/power brakes dont work unless supplied with vaccume from the intake.
be sure the line isnt clogged,id unplug it while running to be sure vaccume is present.

 

It has vacuum,I pinched the line with a pair of pliers to see if the pedal's play and pressure would change. Do you know if the end in the intake has a diaphram? Maybe it is damaged, causing the constant pressure to be affected.When I pinched the line, the pedal was really stiff, but I still had to pump the brakes to stop the truck.