Denny,
There's another port right in front of the large (1/8") one, a tiny one(1/16 or 1/32") that's often blocked with rust. If it's blocked, fluid will have trouble returning to the reservoir.
(If you disassemble the MC, clean it, and look down the bore with a MAGlite, you'll see the two ports on the top of the bore.)
The large port is for fluid to enter the cylinder/piston area(like if you have to pump the brakes); the small port is for fluid return when the brake pedal is released.
Try another MC, or poke around the bottom of this one and make sure BOTH ports are open.
If you're not convinced, drive it and get things hot so that the rear wheel binds-up, then get over to the shoulder and get underneath and crack a bleeder fitting anywhere in the system: if fluid squirts out (not dribbles) and your brakes suddenly "free-up", then "something " is keeping pressure on the system - either push-rod adj or blocked return port.
Have driven several cars and trucks with Huck brakes for years and have not had problems with them.
Good Luck!
