The Stovebolt Site Forums The Shop Area Engine Shop vacuum wiper motor

Hi bolters! Question for Hotrod Lincoln, Ralphy or one of you other pros! I removed, cleaned & put fresh light grease in my vac wiper motor on my 49 AD. Hooked up the vacuum line, and it worked pretty good until I hook up the trans. arms, and then it don't seem to have enough power to pull the wipers. I thought the wiper arms may have hd too much tension so I bent the arms out just a bit, but it didn't seem to help. I recently put a rebuilt motor on my wife's 50 AD 1/2 ton, and same story. I don't know what the heck is going on. I know that vac wipers don't work as well as electric, but they should at least work as well as vac wipers do. These don't work at all. Any thoughts?
Thanks for any advice.
KT

For reliability and safety sake, replace the vacuum motors with the electric counter part. Just because it's not like the original doesn't make it bad. I have one and it works even going uphill. That is just my opinion, take it or leave it,
Scott

They work better on a wet windshield.
Here's a free tip: Use RainX. You won't need to use wipers as much.

You may want to take the transmision arm out of the truck and make sure that the are not binding up. On my 49 it took me about 45 minutes to get mine free and working smoothly. Good luck

I shot some light 3-in-1 oil in the holes of my vacuum motor and worked the arm back and forth. That, coupled with a dual-stage fuel pump with a vacuum port, gives me pretty good performance. It will even push snow around.

Had my vacumn rebuilt in NY for around $65 a couple years ago. Made sure the arms were well lubricated during re-installation and it works fantastically.
Stay vacumn, its part of the the truck's character.

Now if you live up north in Washington or Oregon where is rains most of the time.........

I live in rainy western Oregon and drive my truck in the rain pretty often. My wiper motor is original, I think, and works just fine. It slows down a bit under acceleration but it has enough power to really fling the wipers at high speed. I think you need a rebuild.

I'm planning to add a two stage fuel pump to get some vacuum on on-ramps but there aren't too many situations where it drops to zero on the 261 with an original carb. It could definately use a six pack.

Rain-x does help but it doesn't last very long. Teflon wiper blades help too.

Oh, and it doesn't rain all the time here, we haven't had any measurable precipitation in 6 weeks and are getting a little worried. Tomorrow looks promising though.

I hear it also helps to use the shorter original style blades. I was told that you can put longer blades on but that they generate more friction.

Thanks to all who took time to reply. Well, I wouldn't mind replacing the motor with an electric one, but I haven't converted the system over to 12v yet. I did spray the windshield w/water last night to see if it would help, and it did not. Before I did all this, I took the motor out, and inspected, cleaned it up, and put some new lithium grease in it. The paddle looked good. Tonight, I took out the transmission arms, and soaked them down with lube so they would for sure be free. They seem to be. I put them back in the truck, fired it up, and still the wipers try to work, but they just can't seem to. I guess I will get a rebuilt motor from Jim Carter and try that. I probably won't drive the truck when it rains, but I have to get the wipers working so the truck will pass the safety inspection here, so I can tag it for the road.
Thanks again,
KT

Any chance the vaccumn line could have cracks?

Grease in the vacuum motor isn't a good idea. We used to use Casite Tune-up, in the 6-oz. can to free up vacuum wiper motors, and also the vacuum-assisted shifters on old Chevy passenger cars. The valve that shifts the vacuum from one side of the paddle to the other was bad about getting gummy, and needed as much, or more cleanup than the paddle assembly did. Put a short section of vacuum tubing on the open port of the vacuum motor, and submerge it in the tune-up oil. As the vacuum draws it through the motor, and the control valve, it cleans and lubes the whole assembly, then goes into the intake manifold, and cleans the valve stems on the way into the combustion chamber. Any lightweight tune-up oil, like Rislone, for instance, will work, if Casite isn't available.
Jerry

I was planning to send my wiper motor to www.wiperman.com for a real rebuild - but a job layoff changed my restroration plans to 'on the cheap with manual labor' mode. I disassembled my wiper moter and did the best I could as far as I can see.

I tested the motor today stand-alone - after a minute or so on vacuum, the motor seems to work freely and had a fair mount of torque. But what do I need to do next, after I put the wiper motor back on the car, to lube the wiper system?

I can see 2 assemblies that carry the cables inside the cab, I figure to blow out with compressed air, but am not sure if oiling this is wise.

I know this is a different question - but I plan to remove the front window chrome trim soon to clean the rust underneath prior to a new windwhield install. From looking at the wiper assy. outside the car - it has a single screw, AND a 'spanner wrench' type bolt. Which do I need to be able to remove chrome trim?

ive heard these guys are good. motor repair/

I think you can run 6 or 12 volts to the electric conversion motors. I got mine from Chevy Duty and I believe they offer both.
Good luck,
Scott

Vacuum wipers work best when you spray WD-40 on the glass
or better yet take the glass out and the motor will work fine!!
Honest

Go electric and use rain X!!!!!!!

I sent my motor to Wiperman in NY. To mount a different arm on it, the P.O. brazed a hex nut on the end of the shaft. Wiperman replaced the shaft and rebuilt the motor even though the motor seemed to work fine. I figured it wouldn't hurt to have him go through it since he had it apart anyway. It's got more power since it's got new gaskets & was cleaned and lubed.
Wiperman even took in trade a motor from a newer truck that I had no use for. It paid the freight back to me for the motor for my '46. I just sent it along with the '46 and asked him to give me whatever it was worth to him.
I had weak wiper syndrome on another truck I had years ago. It turned out that I had an intake manifold gasket leak, decreasing the vacuum enough to decrease the power of the wiper motor.

I had a vacuum motor rebuilt by Flicken, the people who bought all the inventory and tools from Trico.
The wipers worked well on a wet windshield going down hill.
Rain X dies nothing for road spray while driving in traffic.
I then added a dual action fuel pump
Then the wipers worked ok at speeds below 35 mph.
Then the dual action pump blew out a diaphram causing the engine to idle crummy cause of the vaccum leak.Then the wipers only worked going down hill again.
I added a large vacuum cannister
The wipers worked down hill and and for 5 strokes uphill.
I bought an electric 2 speed unit ,made in USA
Now the wipers work up hill and at hiway speeds.

One magazine recommended using Vasoline petroleum jelly inside of vacuum wiper motors said it doesn't get stiff in cold weather, as some types of grease might.

Thanks again for all the feed back. I have done everything but replace the vacuum hose from the intake manifold to the motor. I'm going to do that Saturday. The engine is a freshly rebuilt 1957 235. It has all new gaskets in it, but I will check the bolts on the intake to make sure their tight. Someone has replaced the wiper arms at some point, and they seem to have a lot of tension against the glass. Their after market. I'm going to replace them with the original type arms. If that still don't work, I think I may send the motor to Ficken Wiper Service. I thought about getting a rebuilt motor from Jim Carter, but I was impressed when I looked at Fickens site. Thanks for sending that Slow Rider!!

Thanks again to all who have shared their thoughts and ideas!
KT
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1949 3/4 ton Advanced Design

The vacuum motor was designed to move the original style low tension arms and thin wiper blades.A good vacuum motor will do ok with that at the speeds the truck was made for ,like 50 mph tops.With the stock 4.11 gears at lower speeds the engine needs little throttle,high vacuum, to climb slight grades, so the stock set will work ok.But once you put in hiway gears,go faster with more throttle depression,the vacuum wipers are fairly useless, slap themselves to death or are stopped dead.

Get the motor rebuilt. Your scenario sounds just like the one I had on my '49 GMC. Wipers would move a bit but lock up and never really work well. I also took it apart, regreased everything and still no banana. Got a rebuilt unit and I can hardly hold the sucker from wiping across the windshield. Oh yeah, also got the dual action fuel pump. Hardly any slowness when I get the 261 going.

I have heard terrible stories from painter about getting Rain X on the paint. From what i understand about it, it's very hard to get paint to stick if and when you ever repaint.
Thats my 2 cents. I have elc wiper on the 48 panel and vac on the 50. Both work o.k.. But I live in San Diego, and have only used them a couple of times.

The most recent issue (October 2004) of Vintage Truck (nee This Old Truck) has another good "From the Corrosion Lab" article by Bob Adler (a professional restorer of Chevy/GMC trucks). It is about how to make old components work longer and better - one example is how to lubricate/seal and how to "freshen up" a vacuum-wiper motor. It is the first clear description I have seen about how to service a wiper motor (before you give up and have it rebuilt).

Did you know that the intake ports that should be regularly lubricated are pinholes on the outer body of the wiper motor (not the port connected to the vacuum line to the intake manifold)?

A good wiper motor should work fine, even on a dry windshield (except going up hills). A good dual-action pump will work well under all conditions (even on a dry windshield).

I understand that this magazine is available from Barnes & Noble bookstores.

Nonetheless, has anyone found an electric wiper (12v or 6v) that works on a 1954 truck with the stock radio in place?

Tim