Hotshoe, I lived your situation about 2 weeks ago, but no longer. My wipers were sluggish at best, would only go through half of the swing without help. First, I researched Stovebolt.com for previous threads regarding vacuum wiper rebuild, then I went to Wiperman and got what info was available. (I was going to send my motor to him if it still didn't work after I messed with it. I've heard nothing but good feedback from his craftsmanship.)
After noting what was connected where, I used a clutch head screwdriver and pulled the motor out from under the dash. I also pulled out the wiper knob while I was at it. I disassembled the motor and used lithium grease to lubricate the actuator that is cable-driven. I also lubricated the cable with WD40 so that the knob would spin smoothly and the cable would glide.
Next, I took apart the housing. There are two screws (oblong head) that aren't too easy to remove. While these are out, use a hacksaw and cut a little groove in them so that you can use a little screwdriver on them You'll be glad you did. Be very careful with the paper gaskets- they are delicate and probably brittle. Don't forget to remove the air filter- mine was deep dark brown.
I cleaned out all of the disgusting old grease that had been in there for the last 50 years. Next, I used the sage advice of the tribal elders and lubed up the paddle with Vaseline. I gooped it up well, slapped it back and forth and removed the excess. I replaced the filter with some wadded cotton. When it was all back together, it felt air tight and MUCH smoother.
I reinstalled it and the knob. (I just posted a msg about a really cool tool you can buy at your local hardware store for tightening up the knob bezel. Look in the "Tool Chest" section for details.) The first time I twisted the knob to turn it on, I threw the blades off of the arms. It worked wonderfully for nothing more than the cost of the goop of Vaseline.
Now I'm having to buy new arms and blades to keep up with my supercharged vacuum motor!
One of my vacuum supply lines is new, but the other is fairly brittle. I'm going to replace that when I get the new blades/arms.
One word of advice: if you live in the monsoon zone, and you plan to drive your truck during the monsoons, you really should give careful consideration to going the electric route. There is a reason all current production uses electric wipers! I live where it is dry and have no plans to drive in the rain. The wipers are there to pass state inspection and an occasional gotcha shower.
Bill
