To bench bleed a MC I clamp the MC in a vice, Connect a short brake line to each circuit (steel or rubber), bend the lines around to put the open end back into the reservoir, fill the reservoirs with brake fluid to a level above the open end of the lines you just installed, insert a screw driver into the MC push rod opening and slowly start pushing the plunger in and out, when you stop seeing bubbles coming out the brake lines on the push stroke you're done. Remove the lines, install the MC cover/cap and install the MC in the vehicle.
Hope this helps,
Mike B
