The Stovebolt Site Forums The Shop Area Interiors Wiper Motor

My '51 3100 vacuum wiper motor will only make one sweep then stop. I then turn the dashboard switch in the other direction and the wipers make a pass in the other direction. I don't imagine it was designed to work like this so I guess something is not complete. Any suggestions.

Do you hear any vacuum leak? I have a suspicion that it has a bad seal. Mine is basically doing the same thing and I plan to buy a 6V electric motor that fits the same location. They are spendy but I think worth it to eliminate the hassle of the vacuum motor.

LINK

From what I understand there are only 1 or 2 people in the country that have the parts to rebuild the vacuum motors.

My vac motor was sluggish so I squirted 3 and 1 oil in all the holes. It then worked pretty well (not on hills, of course) until I switched to an electric motor.

I can hear the motor running, but it does not sound like there is a vacuum leak. I will check it out closer. I would like to keep the truck original wherever possible. If the wipers turn out to be a safety issue, I will put in the electric motor. I saw a spring mechanism in a diagram of the wiper assembly. Does anyone know what that spring does?

Might be good to fix it now before it becomes a safety issue ( at the worst possible time.)

Take your motor top off and clean the inside with brake cleaner then lube everything with vasoline and reinstall 95% of the time that will help also hiding and hooking up a vacumn reserve tank under the dash will stop the wipers quitting on acceleration

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Thanks for the links to previous posts and different methods to try before sending the motor out to be rebuilt.
I will try these before deciding whether to rebuild or replace with an electric motor.
One more question, does anyone have a suggestion of how to bench test the vacuum wiper motor? Obviously I need a vacuum source to test the motor. Since the wiper motor is out of the truck, and the truck is packed away for the winter, I can not use that. Does anyone have any suggestions how I can get the recommended 21 inches of vacuum need to run the motor?

You can switch the leads on most compressors and they will pull vacuum instead of blowing air. Not sure about getting the 21 lbs, or how you would gauge it?

Thats another use for my vacuum pump. Besides vacuum bagging and
degasing epoxies and such. It does come in handy for checking a
vaccum wiper motor or vacuum fan.

All the oil and grease in the world isn't going to help your
wiper motor if the piston seal is shot and 98% of them are shot
after 60 years of use.
The "one" rebuilder that is left will put all new parts in the
motor and it will work like it did when it was new, which
wasn't all that good to begin with. Even with the dual
fuel/vacuum pump they aren't very reliable. Quite simply if
vacuum wipers or appliances were reliable they would still be
using them today. The only real for sure fix for dependable
wipers is to upgrade to an electric unit. If you want to stay
100% original with your AD truck then you will have to put up
with unreliable winshield wipers that was part of it even back
in the day.

Denny Graham
Sandwich, IL

Thank you to everyone for their input and suggestions for my wiper motor question. After trying to fix the motor myself and making no progress, I decided to have the original unit rebuilt. I know, many people said to put in an electric motor and be done with it, but my goal is to rebuild my truck to original condition, when ever possible. Since this truck won't be my daily driver, I think I can live with the inefficiency of a vacuum motor. I had the motor rebuilt by the Wiperman, and it works great. For a little added vacuum I will rig up a vacuum reserve tank, as suggested in the posts. I also found an easy way to test the motor as I tried different fixes. I simply hooked it up to a vacuum line in my every day car since my truck is packed away for the winter.