Bleeding brakes.
 

On my '78 I changed the line that runs from under the cab at the connector, up to the block on the rear end (due to the shortend wheelbase). The line wasnt loose long, but all the fluid ran out of the master cylinder. I tried to bleed the brakes yesterday, but I can't get any fluid out of the wheel cylinders.

Do I need to first bleed the master? How do I go about that? As far as I can tell the fronts are ok, b/c its still full of fluid.

Thanks
Paul

Try topping of the master cylinder with fluid (leave the cover off) then open the bleeder screws at the rear wheels. After that just sit back for about an hour or so. This is called gravity bleeding. If it works correctly, you will have brake fluid dripping from both screws. Then do a traditional bleed on the system. Good Luck.