Hello All , I have a `56 Mainline , trying to get wipers working correctly . Wipers can barely lift themselves from the park position on the screen
when I have them hooked up to the DA fuel pump . When I connect the wiper motor directly to the front  manifold port , they work fine,
even when I rev the engine . Vacuum reading off the hose to the vacuum wipers is roughly 20 Hg inside the car . DA pump is supposed to be rebuilt,
is it possible for DA pump to read 20 Hg , but not able to operate the wiper motor ?
Any input would be much appreciated , I must be hooking something up wrong .
Regards,
John.

do you have the lines to fuel pump on backwerds.the pump should suplement the engine when engine vacume drops. if the pump does not help ,just get a small propane cyl and convert to a extra vacume source with a check.i am not a fan of the dual dyaphram fuel pumps,but if it is hooked up in corectley it is a neg help. henrey should have  had a kick re the vacume wippers, especialey with a standerd trans.

Thanks 2721955Meteor , I re re-checked my lines , they`re on  the correct way , manifold line to the outside , wiper line nearest the block.
I am beginning to think the vacuum side of the pump is failing somewhere. Old `56 Mercury Shop Manual says to pull the lines off at the
rubber connections on top of the pump , and check pressure there ...no less than 10"Hg. I will have another look today.
Regards,
John.