I read where you followed the manual but have you gone to the e-brake cables and undone the clevis pins? Then you pull the cables forward, turn the clevis until the holes line up and re-insert the pin. Unless the parts inside the brake drums are not hooked up to the shoes correctly or at all.
Mine were not holding until I did that cable bit. They are not locking however and I found that the arm and rods in the cab need rebuilding.


1949 Chevy 1/2-Ton
"Sedgewick"
In the Gallery
1989 Caprice