You might try this fix before sending it out. A lot of problems with vacuum wipers is because the flapper inside the unit dries out. Try this with a helper
From the engine compartment, take off the hose that goes to the wipers. Insert it in a bottle of ordinary brake fluid and work the wipers manually up and down (this is where the helper comes in) about ten times. Usually, the vacuum created will suck in the brake fluid. Let it sit overnight so the flapper soaks up the fluid. Then try it. If the flapper is dried out, this should fix it.
Before doing this, put some rags under the wiper unit as it may drip some. You will get some smoke when you first start the car after doing this, but it will go away.
Throw the remains of the brake fluid away.
54 Victoria 312; 48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ