The Stovebolt Site Forums The Shop Area General Truck Talk Vaccum wipers, a few questions....

Useing some spare parts I recently picked up, I was able to get my vaccum wipers to work somewhat but not good enough to drive in a rainstorm just yet.
My truck is a 49 3100, a few questions:

1) My 216 is drawing around 17" of vaccum at idle, is this enough to power wipers?

2) when I turn the wiper switch all the way "on" the wipers will quickly sweep to the "up" position and most times just hang there. Sometimes they will reverse and sweep back & foreth but most times I have to slightly move the switch back alittle to get them to sweep, is there an adjustment without opening up the vavccum motor?

3) I'm still 6v and plan to stay that way until the electrics fail, anyhone have experience w/6v electric wipers?

4) Theres a rubber cup type keeper that keeps the switch arm secured in the vaccum motor's control arm, is there a source for this?
Thanks
Dave

The vacuum motor is probably dried out. You can not get parts for these but the can be sent out for a rebuild. Try taking the top off very carefully and cleaning the insides, adding some soft grease, and a little oil to freshen up the leather paddle. You may find it starts working pretty good. 17" is plenty for them to work. A little rain-x or wax on the glass helps.

Check with the Filling Station or any of the venders on this site for parts. See links above.

Joe

#4 I got all my vacuum wiper arm parts from American Classic (www.americanclassic.com).

For what it's worth...6v is good stuff. Clean all the contacts and make sure your wires are in good shape and you shouldn't need to change over to 12v ever. Classic Truck Parts sells a complete basic 6v harness for $150 that is a breeze to install.

Here's the grommet you're looking for:
http://www.classicparts.com/1947-53-Wiper-Control-Link-Grommets/productinfo/67-661/#.Ujm0myko6ig

And as far as the operation of the wiper motor, the piston or
paddle as some prefer, dries out over the decades and needs to
be replace with a new one. They are not available to the
general public any more and the only one that I am aware of that
can replace it is the Ficken Wiper Service aka The Wiper Nan at
http://www.wiperman.com/
You are going to hear dozens of reports about how some guys
disassembled their wiper motor and re-greased it and it works
like new now. I don't believe any of it. When the wiper was new
it would pull with enough power at normal vacuum to handle most
weather conditions. Don't expect it to clear snow from the
window though. Again, the piston fabric is impregnated with an
unknown substance and as it dries out it will not make a vacuum
tight seal. Vacuum is low volume so for it to be affective in
such a small chamber it has to be 100% vacuum tight, from the
connection at the manifold all the way thru to the motor.

Denny Graham
Sandwich, IL

There was recently an article in the VCCA club magazine about how to recondition a dried out vacuum wiper motor while leaving it on the car/truck. A few posted in the chat room following the article that the technique works great. I passed the magazine containing that article on to other so I don't have it in front of me. If you register and post a query on the VCCA chat site I'm sure someone will know the process off the top of their head.

I have an NOS motor for my 38 project. I had a similar problem with it. I discovered that the little valve that controls the direction switch over was binding. I got it freed up and it now works perfectly.

As for vacuum, the fuel pumps that also supply vacuum generate around 14" so at 17" you should be good to go.

I swear mine did work like new for at least a couple minutes after "reconditioning". I fixed this by deciding if the forecast calls for rain the truck stays home in the garage as I envision a good downpour at highway speeds being a challenge for even a brand new vacuum wiper motor. I remember laughing when a guy posted that the electric replacement he bought had 2 speeds...too fast and way too fast.

After you rebuild and get the vacuum motor running correctly.
You could upgrade to a Double Action Fuel and Vacuum Pump.

As for 6v electric wiper motor check out these.
1947-53 Stock Choke Cable Chevrolet / GMC Truck This unit will clear the stock CHOKE CABLE.
1947-53 Chevrolet / GMC Truck
The above are only 12 volt motors you have to get a
6 to 12 Volt Power Inverter (scroll to bottom of page) to boost the juice.
There might be other venders that make a 6 volt wiper motor for your year. Then no need for boost juicer.

Thanks,

Here is a 1949 Wiper motor electric conversion kit, 6 volt
Should do the job.
Or Wiper Motor -6v 2 Speed With Park

Both of mine were rebuilt years ago by wiperman, I have no complaints. The few times I have used them, they were to fast, my 250 has very high vacuum. The real problems is the springs that hold the wiper to the glass is very weak so you very little down force. Mine mostly throw off the big drips, the wind clears the rest.

Joe

Now don't get all excited about the Double Action Fuel and
Vacuum Pump. It taint all that it's cracked up to be and it
don't add all that much to the equation. When I rebuilt my 216
5k ago I added the Double Action Fuel and Vacuum Pump.A few
pictures of the installation:
http://www.pbase.com/dennygraham/5591547_fuelvacuum_pump

Just the other day here in Chicago we had a major downpour
which me and Ol' Blue got caught in. Had to navigate about 30
miles in driving rain where some cars were pulled over on the
highway. It was out in the country where you expect to run at
speed and I was running at around 50-55mph. With the throttle
in the acceleration mode the blades were dead in the water,
came back in cruise and went slap happy with the throttle off.

As fur as the clearing the glass and staying put at speed they
did just fine, but both blades and arms are new and I use
Rain-X on the windshield.

Denny Graham
Sandwich, IL

Denny, GM must have changed the holds on your newer truck, my '37 has very weak springs which do very little. Mine acted the same way as yours, they go like mad at cruise or down hill, and pretty much stop up hill. If I drive very careful, I can keep them moving.

Joe

Denny, I solved that problem by hiding a vacuum reservoir can under the cab. The double action pump keeps the can full (or empty) and I have plenty of oomph to keep em wiping when I accelerate even with my vac defrost fan running.

Well now ya got my curiosity up I always figured I'd need a
pretty BIG tank to hold the vacuum up for any measurable
amount of time.
I've got an empty 50 lb. Freon tank that I cam easily plum in
series with the wiper motor. Think I'll do an experiment and
see it that would indeed work. Gotta say, I don't think even
that 50 lb. tank would be a large enough volume to make much
of a difference.

Denny Graham
Sandwich, IL

How about something like this, if you have a 12 volt system?

Moderators note: He was referring to an electric vacuum pump.)

Thanks for reply's and info.
Update:
I ordered and installed new wiper arms & blades and those rubber grommets to keep the control rod connected. I had to pull the vaccum motor to get the grommet installed and while I had it out I decided to squirt alittle 10w30 down into the vaccum port of the vaccum motor then shook it up real good in hopes it may get worked into the chamber with the paddle and perhaps lube and seal it up.
After getting everything reinstalled and hooked up I gave the wipers a test and that old vaccum motor didn't have any problems working both wipers in both directions. They would work full speed and also work slower. I could slow them down to the point they would barely move.
It appears that the oil did as I hoped.
I don't know what the long term effects the 10w30 will have on the paddle and seals. Good or bad I do not know.
But at this point I now have fully functional wipers

Dave

Thanks for the update. Sounds like you are ready for some snow and ice !

Joe