Some manuals say the two bleeders are for draining the caliper completely
when changing fluid and bleeding. Top for bleeding, bottom for draining. I
think the real reason is that only one caliper has to be made bringing the
cost down below the price of adding an extra bleeder screw. If you're
trying to bleed use the top one just like a normal vehicle and you
shouldn't have any problem.
>i have an 85GL.  2 bleeder screws on each caliper.
>i open 'em all the way and don't get any fluid no matter how much i pump.

 Greetings from Michigan's Upper Peninsula
 Jeff & Jean-Marie Diebolt
 mailto:jdiebolt@up.net