What grease did you use? I used Vaseline petroleum jelly in mine (got the tip from Wiperman, IIRC). Are you bench checking it or doing a test after it is assembled? Reason I ask is that mine doesn't flap very well with the blades on a dry windshield. No problem with a wet windshield.
Did you put in a new cotton filter? Mine was pretty gummed/dirty. If it is dirty, I suppose it could act like a plug. Also, if the gasket looks like it is 54 years old, you might have some leakage there. It needs to have a good seal to work well.
Finally, where the paddle swings, what does the casting look like? Is it scored from abrasive particles/petrified grease grinding away at it? I think you'll have better operation if the swing region that is in contact with the flap is smooth. It is possible there is some scoring that is slowing down the mechanism- if so, I'd polish it out with wet sand/rubbing compound.
Like Joe H said, these things aren't too complicated. The problem and solution hopefully are right there in front of you.
Alternate resources:
http://www.tbirdranch.com/wipmtrep.htmlhttp://home.comcast.net/~sday77/binky/repair_vac_wipers.htm
Good luck.
Bill
