I've got an issue with my NOS wiper motors. They work fine when I have no arm or blade attached, but when you add the tension of the arm and the blade against the glass, they struggle to work. I'm working with the guy who sold me the motors and arms, but was wondering if anyone else ran across this and has a quick fix...except don't drive in the rain.

I'll display my rank ignorance here, it comes easy to me.

I'm assuming a 32 uses vacuum to wipe the window. If so, the wiper motor inhales air to satisfy the manifold vacuum connection. In doing this for 75 years or so, the internals of the motor get clogged with airborne particulates. Sometimes there is a gauze or felt filter on the air inlet that intercepts some of the the dirt. It may help to clean that.

A more thorough job would be to disassemble the motor on the bench and wash it out. The original assembly grease may have by now polymerized into a hard goo removable by something like carb cleaner. Your instincts will tell you the type of lubricant to put it back together with; graphite, white lithium grease or what have you. Make sure the mating pieces are flat and true and you may have to make a new gasket, the obvious point being that a vacuum leak will degrade operation.

And of course check the vacuum line from the manifold, in fact, have a look at that first; it's easier to replace. The vacuum motor will never have the torque of an electric so for on-car testing, I simulate rain with a garden hose in order to lubricate the blade.

In the future, make it a practice to never drive uphill in the rain.

oops, I re-read your post, you already said that.

Agree. I'll get back to you with exact instructions of what we did.
On mine, the linkage between the two wiper blades was very gummed up as well, but you don't have that problem, I'm sure. But for anyone else wondering why their later-model wipers are sluggish, some PB blaster at the joints and some white lithium grease makes a big difference.

Years ago before electric wipers, we had some weak truck air wipers with problems like the ones indicated.

We noticed that as long as it rained and the windshield was wet, they'd work fine.

We decided to not operate them in dry weather, cured the problem, really!

Wayne

Okay, here it is. This was for a 1940 unit, so there may be some differences, but I think the advice is very good.

First of all, I found that it's not a good idea to disturb the cover of the motor, because the cover to body gasket is really critical and very difficult to make. So, the idea with this approach is to just coax the little puppy back to life by softening up the dried up grease on the leather paddle seal.

The little cover on the side with the tiny screws covers the switching mechanism. Behind the switching mechanism is the air inlet. I think that when you remove the cover, the mechanism is free to come out - so be careful.

I cleaned this mechanism, using PB Blaster. Then, I introduced a cocktail of 2 drops PB Blaster, followed by 2 drops WD40, followed by 2 drops 10W30 into the air inlet hole behind the switch plate. (Be sure it's five o'clock somewhere.) You can use another 2 drops of WD40 as a chaser for the oil, if you like. The idea is to soften up the remaining grease and the leather paddle inside and leave a little trace of oil on the leather to help it seal. Turn the part to all different orientations to distribute the oil.

If you want to stay away from the switching mechanism (which is like a Swiss watch), you can try the same technique from the vacuum connection tube. But, going from the inlet is best. Just trying to introduce the cocktail into the vent hole on the little cover doesn't work very well, because there is a gasket behind the hole to keep debris from fouling the mechanism.

If you want to test the part with engine vacuum, reassemble and try it. But be careful, when it's working correctly, it can take off your finger.

Now, if all is well, go ahead and mix another cocktail. Follow your own recipe for this one.

If this works for a short time and then quits again, it means the leather paddle is too far gone to save.

Ken, maybe there will be something here that will help..B

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