Retired Wrench, think you could post a picture of that jar of Trico grease for us to see???? I’d like to add that to my reference library, tks.
Eightfan, like the man said, these are pretty basic vacuum motors, yo problem is a vacuum leak most likely at the piston.
Once the seals wear out and allow any vacuum leak at all, there isn’t much you can do with them, all the grease in the world isn’t going to make it work any better. Vacuum devices have to be absolutely vacuum tight because they operate in a very narrow band of negative pressure. Absolute perfect vacuum is only about 30inHg. If your engine is in top-notch shape it will only pull about 22inHg. If your vacuum motor and system had a perfect seal it would only be capable of producing approximately 25 to 30lbs of force on the paddle at this level of vacuum and this does not take into account any of the friction drag produced in the motor, linkage, transmissions or wiper blades.
Unfortunately the few re-builders have bought all of the Trico surplus parts up so they have a corner on the market. None of them that I have contacted will sell any parts and a new paddle is the only thing that will seal properly. I’ve not been able to find a material that would work as a replacement. The seal is a woven fabric that is impregnated with something, which I have been unable to identify. As close as I can figure the was some sort of grease possibly with graphite in it.
I have a Welch vacuum pump used for evacuating high vac systems that will pump down to 10-3rd or about .001 atmosphere, I use that to test a vacuum motor after I’ve restored it. Even at that high of a vacuum often the old paddles don’t seal enough to produce a lot of torque so you couldn’t expect the vacuum from an internal combustion engine to drive it.
There really was a reason that the industry went to electric wipers!
Denny Graham
Sandwich, IL
