Some people recommend bench bleeding the master cylinder before attaching to the truck. I have done it your way and also bench bleeding and both ways were successful. So start adding DOT 3 or 4 to your master cylinder and as you bleed be sure you don't let it run dry or you will introduce air into the system. Start with the wheel cylinder farthest from the master cylinder which should be the left (driver's side) rear, the right rear, left front and finally right front. Look for leaks in your new system.
It is easiest to have a helper to push on the brake pedal as you bleed but you can do it yourself with those commercially available vacuum systems or simply putting a long hose on the bleeder screw into a container of fluid so air doesn't suck into the cylinder when you release the pedal (when working alone).
If you don't have tight pedal action when finished consider adjusting the shoes tighter before proceeding with more bleeding or quitting in frustration.
Kent
