1956 wiper motor rebuild

[Rob Leech]

I have rebuilt my 1956 wiper motor and I have ended up with two problems. I know there have been other posts about this, but I can no longer find them, or they did not answer my questions. The stroke of wiper blade is now much shorter than it was originally. I took many pictures and put it back together just as it came apart. Can't figure out how to make the wiper blade swipe go further on the glass. I just rebuilt my engine and put new vanes in the vacuum pump. It seems like a strong vacuum. Also, it seems like I had vacuum at the controller tube going to my washer bottle. Again, I followed my pictures, and it really seems like there is only one way that it can go back together. Everything is sealed tight on the motor, and I don't feel any air leaks. Does anybody have any ideas what might have caused the vacuum loss at the controller. I did not take the controller apart. One more question, should I have vacuum at the controller tube all the time, or just when the wiper motor is running? Thanks for your thoughts.

[CadillacFanBob]

@Rob Leech

Did you measure vacuum with vacuum gauge at vacuum pump circuit?

Where were you able to find replacement vanes for vacuum pump?

Bob

[Rob Leech]

I am aware of the cable tensioners under the dash. Liked to have never got the adjustment button loosened up. Used lots of penetrating oil and mild taps with a rubber hammer. Nothing adjusts when I push and hold the buttons. Cable tension feels pretty tight on one side and loose on the other. I will continue to try and figure out why they don't adjust. I assumed that the length of rotation was controlled by the motor. You may be right. I have a parts car and I will change them out. Thanks for the suggestion.

[Rob Leech]

Hey Bob, I did not measure the vacuum, I just guessed that it was enough because the wipers are working, although they are pretty slow. I will use a gauge and report back. What would be a good reading? I did not find new vanes, I carried them to a local rubber and gasket company. They did some testing on the rubber and made new ones. They felt hard and they beveled the edge just like the old ones. Are you guessing the vacuum being low might affect the controller? I am pretty sure I had vacuum there before I tore down the wiper motor. I had capped it off with a rubber plug. Thanks for the suggestion. I will measure my vacuum pump and let you know.

[The Tassie Devil(le)]

I am aware of the cable tensioners under the dash. Liked to have never got the adjustment button loosened up. Used lots of penetrating oil and mild taps with a rubber hammer. Nothing adjusts when I push and hold the buttons. Cable tension feels pretty tight on one side and loose on the other. I will continue to try and figure out why they don't adjust. I assumed that the length of rotation was controlled by the motor. You may be right. I have a parts car and I will change them out. Thanks for the suggestion.

If the adjustment is done the same way as on Chevrolet, don't you just push the wiper arm shaft inwards from the outside of the car to release the adjusters, and then spring pressure tightens the cabling?   Or, am I thinking of another brand?

Bruce.

[Roger Zimmermann]

Bruce, I'm not sure but I believe that the wiper arms must be removed to adjust the cable tension. In fact, the shop manual is saying that.

[Rob Leech]

That is correct, the wiper arms have to be removed. I have done that and cleaned up the springs and lubricated them. I took the cable off on the loose side and reinstalled it by the manual. The springs just don't change when I push and hold the button. I will study the parts car and get back. Thanks

[Lexi]

I have a box of wiper related parts off of a '56 in case you are stuck. Would have to look and see exactly what is there. Parted out a spare motor recently but there are some wiper "transmission" parts still there. Clay/Lexi

[CadillacFanBob]

Disconnect vacuum pump hose leading from crankcase at check valve on cowl, hook up vacuum gauge to vacuum pump hose, with engine running vacuum should be 20 inches minimum at 3600 RPM.

make sure windshield is wet when testing wipers.

Approximately what did it cost to have vanes made?

Bob

[Roger Zimmermann]

This test is only making sense if the vacuum manifold is in good condition, otherwise the vacuum from the pump is diluted with the vacuum from the intake manifold. I wrote something about its repair somewhere in this forum.

[fishnjim]

Why I went to Newport and bought an electric set.  Bolts right up but some wiring to do.  Works great, wet or dry, and no slowing down. 
Vacuum anything will drive U nuts. 
The motor flapper changes direction when the vacuum maxes, causing the switch, so it's getting too much too quick and not completing the stroke.  There was a stop on the flappers but if you didn't touch them they should be OK.  I doubt the loop tension has much to do with the short stroke.  That just keeps enough tension to prevent them from "slapping".  It's possible it could be way too tight or something/nto strung right or off the hub, making the stroke not complete.
It's changing direction prematurely.  There's a diaphragm in the manifold that goes bad to look at but usually the reverse, not working.  Otherwise, not much else can go wrong here, except leaks which have the opposite effect.   
We're just not used to the old systems and have to read and weep over stuff.  It was written at a time when they knew what they meant and that's nto always the case today.   www.rebuildingtricowipers.com  [apparently Ficken lost his "wiperman" domain rights to a foreign company.
If the new vanes weren't "right", it wouldn't work at all because if they don't slide, they can't make a chamber.  I don't know what happens if it's "too good" but can only go so fast with rpm.
You should've had a bunch of vanes made, and sold them to pay for your set plus...

[Jay Friedman]

In my experience the best thing to do when you have a vacuum wiper motor problem is to give it to www.wiperman.com to fix.  They charge $!35 including shipping back to you.  They've done several wiper motors for me to my complete satisfaction, including the one on my '49 which works perfectly.

[CadillacFanBob]

@Rob Leech I sent you a PM

Bob

[Rob Leech]

Wow, so many replies to this, it has been hard to soak it all in. Thanks to all. My vacuum reads 15 at idle and about 18 when revved up. Thats about as high as it goes. I took the wiper motor back apart and studied a lot more about it. I did find that the tunnels to the valve in the side door cover were clogged up. I got them freed up. I also found an almost correct paper gasket set on eBay. I had to modify it slightly, but it does fit. I lubricated the flipper with a very light oil instead of grease. The wipers are working better, but not on a dry windshield. The stroke is longer than it was, but it seems it should still be longer. The first stroke seems to be fine, then it is a little shorter after the first stroke. The squirters are working perfectly. I did not know that the vacuum vanes are hard to find. I get 18 to 20 on my vacuum gauge with the set they made at the gasket company. I don't know if that is good or bad.

[Rob Leech]

Here is something else I learned about these wipers. If your cables to the transmission are loose, the manual tells you to push down on the outside stem and the cables will adjust automatically. That would not work on mine. Using two people, one person push down on the stem were the wiper arm attaches. With the dash pad removed, the other person can see two metal plates with spines in the transmission separate from each other with the stem depressed. Insert a flat blade screwdriver between the plates and twist it right or left, depending on whether your cables are too loose or too tight. When the cables are snug, release the pressure on the outside stem and then slide the screwdriver out from between the two inside plates. This worked to adjust my cable tension, the springs would not self-adjust the cables on mine.

[CadillacFanBob]

That is great on your vacuum reading for the vacuum pump source, service manual calls for 20 inches of vacuum at 3600 RPM.

Did the new vanes the gasket company made fill the complete cavity wedge the sit in with spring pushing outward?

ALSO see Self-Starter magazine article January 2021 from @Roger Zimmermann for Vacuum manifold on firewall area.GREAT Article.

Seal/gasket for windshield wiper check valve part # 1464610 sold by David King CLC member, as listed in Roger's article.

Bob

EDIT: I AM LOOKING FOR OLD ROTARY VACUUM PUMPS TO EXPIEREMENT WITH.

[dn010]

Can you tell us which gasket set you got through eBay? I am soon to put together the vacuum motor for my 57 and need these gaskets soon.

[Rob Leech]

It has been a while since I started this post. Here is where it stands today. My vacuum pump is no longer working. Maybe the vanes did not hold up, not sure what is wrong, but I don't want to remove the oil pan to check it just yet. The stroke of the wipers seemed to be controlled by the dash switch. I had to slowly turn the knob and the length of the wiper stroke changed from short too long. It appears to be a two-speed wiper set up. My cables are tight under the dash now by using the screwdriver twist method I described earlier in this post. So, I still have no wipers because I have no vacuum. I tried hooking to the carb, but that didn't work. I will post more if and when I bother to drop the pan again to check the problem with the vacuum pump. Thanks to all who answered questions. I hope we all learned a lot about vacuum wipers.

[5390john]

I read  the Self Starter article for the firewall manifold check valve repair when that issue arrived. I contacted David King and got the part, rebuilt the manifold and it made a HUGE difference in the wiper's performance. Highly recommend doing this, even if you don't think you need to.
This was one of the wiper/washer system projects that I refer to in my other thread on washer pump rebuild questions.
John Adams