dj........when you push the plunger it will compress the brake fluid......so even if you had the front end of the mastercylinder closed it would still squirt out some if you have the top vent cap removed.....it sounds like a gumbed up flex brake line to me.......they will get nasty before actual solid lines get gumbed up.......try the bench test.....then if its working good re-install and then disonnect the flex brake line in front from solid line.......you will find out quick if thats the problme........god..arent brakes fun...wink wink