1950s 1957 Vacuum Wiper Conversion

[Kurt Kjelgaard]

Hi,

I am planning to convert from vacuum to electric wiper motor. It seems to be fairly straight forward.
Vacuum motor out - electric motor in - hook up electrical supply with new switch, plug vacuum sources etc.
However, I want to use the existing controls for both wipers and washer, i.e. no modern switch(es) in the instrument panel if at all possible.
Original washer system should still operate with vacuum.
Has anyone out there tried this or have any ideas how to do it?

Kurt

[Roger Zimmermann]

Once I had interess for the conversion. I did not pursue the project because I had to add another switch and the vacuum washer was no more coordinated with the wipers.

[Kurt Kjelgaard]

I understand - I have the same reservations, but maybe somebody has figured something out?

[Cadman-iac]

Hey Kurt,

The Cadillac vacuum wiper motor is controlled by a cable coming from the control switch, and it slides a valve that allows the vacuum into the motor. Since there's no electrical connection needed, the control switch isn't compatible with any newer electric wiper motor made by the aftermarket.
  There is another way though that I've found. GM used electric wiper motors on the tri-5 Chevrolets as an option, with the vacuum motor being used as standard.
The control slides on these is the same design as what Cadillac used, at least it was for the 56 models, which is what I have.
I used to be heavily into the 55/56/57 Chevys, and I happened to still have one of the electric wiper motors from one. Since I've experienced how vacuum wipers function in bad weather, I decided that I'd figure out exactly how to use this particular motor on my 56 Cadillac.
One obstacle was that the motor begins rotating in the opposite direction, which if just bolted up to the Cadillac, would try to move the wipers from the parked position downward onto the hood instead of upward and across the windshield.
After looking at the whole system for a while I figured out that if you swapped the cables that drive each arm on the center drive part, then the arms will operate correctly.
The original control switch can still be used and your washer system can still coordinate with the wipers.
I posted something about this here a while back but it was before the change to the forum where you can specify what decade you are referring to or searching for.

I guess I should ask you if your 58 has cable-driven wiper transmissions/arms or if it's got hard linkage. My workaround will only work with a cable driven system.
I hope this helps you figure out how to convert your car to electric wipers.
I have worked out all the details to do this with my car, but since it's still in about 100 boxes yet, I have yet to test it out with everything installed. But as far as I can tell it will work great.
If you have any questions, feel free to contact me or I'll be happy to answer them here.

  Rick

[Cadman-iac]

  Here's a picture of the tri-5 Chevrolet wiper motor that I'm using on my 56 Coupe De Ville. As you can see I've already got the coordinator mounted on it, and you can see the slide mechanism that turns the motor on. It's the plastic piece that moves an electrical switch beneath it, operated by the original wiper control  cable.

Well, I would have posted the picture, but there seems to be an issue with the website. I'll try again later.

Ok, here's the picture finally. Got it to load this time.

[dn010]

1958 is still cable driven. The only problem with the Chevy wiper motor is that it costs as much, or more for a restored motor, than the Newport Electric wiper conversion kit.

[Cadman-iac]

1958 is still cable driven. The only problem with the Chevy wiper motor is that it costs as much, or more for a restored motor, than the Newport Electric wiper conversion kit.

 This may be true, but he had asked for a method to use the existing wiper switch, and as far as I know, this is the only way to do that, so I offered it as a solution.

 Rick

[Kurt Kjelgaard]

Thanks for the inputs - the Chevy motor approach is interesting.
Initially I was thinking Newport with an arrangement near the motor to activate the newport rotary switch with the original cable. The cable has a linear movement of about 13mm which would have to be converted into turning the switch axle enough to trigger the switch. Alternatively, an adjustable delay system rotary switch might be used.
Or an external sliding switch could be adapted.
These approaches, however, leaves the washer vacuum activation question unanswered.
Ideas?
Kurt

[Cadman-iac]

Thanks for the inputs - the Chevy motor approach is interesting.
Initially I was thinking Newport with an arrangement near the motor to activate the newport rotary switch with the original cable. The cable has a linear movement of about 13mm which would have to be converted into turning the switch axle enough to trigger the switch. Alternatively, an adjustable delay system rotary switch might be used.
Or an external sliding switch could be adapted.
These approaches, however, leaves the washer vacuum activation question unanswered.
Ideas?
Kurt

Using the original control to activate the new control is an approach that I haven't heard of or thought about before. I suppose it could work, but if I were to try this I would put the new switch behind the dash to keep it out of sight and to protect it from the harsh environment under the hood. It sounds like it over-complicates things though, and you still have to find a way to get your washer system to coordinate with it.

The biggest, (only), difference between the Cadillac and Chevrolet systems is in how the cables are routed between the wiper transmissions/(arms) and the drive pulley. Chevrolet just had them in switched positions on the drive pulley.
I hadn't thought about this until now, but a Chevrolet vacuum wiper motor probably has the park position in the opposite side of its travel just like the electric wiper motor does, so when used on the wrong vehicle the wipers work in the opposite direction.
The simple solution is to swap the drive cable positions on the center pulley and then the Chevrolet motor will work just like a factory part would.
Something to consider too is the availability of whichever motor you go with. Cadillac aftermarket parts are scarce, but tri-5 Chevrolet parts are popular and abundant.
That's one major reason why I decided to go with the Chevrolet motor. I tried to locate a Cadillac electric wiper motor with zero luck.
But it's your car, your choice. I'm only offering my experience since you have asked for alternatives to what you found in the aftermarket.
Yes, a rebuilt tri-5 Chevrolet electric wiper motor is expensive, but you shouldn't ever need to replace it again, and with the cable swap being the only modification necessary, it will work with your original wiper control switch and washer system.
There may be an original Cadillac electric wiper motor out there somewhere, but for how much, and in what condition?

Rick

[Kurt Kjelgaard]

Rick,
Thanks for taking your time with this.

I have spent some time now studying this trying to figure how it works.
Correct me if I am wrong in the following:

The original system can be divided into three parts:

- The wiper motor itself, actvated by cable
- The washer system, activated by pushing the button to relieve vacuum from the coordinator input (makes the piston suck up fluid)
and then releasing the button to restore vacuum in the coordinator (making the piston pump fluid to the nozzles)
and
- The interaction between the washer coordinator and the coupler on the motor to start and turn off motor.

From this follows that you can run wipers and washer as separate systems from original controls.

Without a coupler (which I don't have), if you want to wipe after spraying, it must be done manually.

Have I understood this correctly?

[Cadman-iac]

 It's been quite a while since I've messed with mine, but if I remember correctly, the coordinator initiates the washer pump action when you press the button down, and when you release the button it activates the coordinator, which in turn turns on the wiper motor at the correct time so your washer spray is hitting the windshield before the wiper blades obstruct, or disrupt the spray, maximizing the water that hits the glass and not just bouncing off the blades or arms.
 I'm not sure what you mean by the "coupler". The piece that is mounted on my motor in the picture I posted is the coordinator, is that the part you are calling the coupler?
 And as far as I know, (I'd have to read up on it more I guess), you can not just spray the washers without the wipers coming on at the same time, as that's the function of the coordinator.
 Your system may work differently from mine, but once the washer pump is activated and the wiper motor is turned on, after the washers stop spraying, the wipers continue to operate until turned off manually. (I think)
 I may have to test my system on the car body and see if that's correct.
 But again, it's been 3 and a half years since I've done anything with mine before I put it all in a box until I'm ready to install it on the car. The tests I did were on the bench with a battery and a vacuum pump to operate both the motor and the washer pump.
 I remember testing it as a system after I rebuilt the washer pump with a rebuild kit I got from McVey's. I took a lot of pictures of it at the time and posted the rebuild on here as well.
 If I haven't answered your questions or if you have more, let me know. I'm glad to help if I can.

 Rick

[Kurt Kjelgaard]

The coupler is the part on the motor  - the coordinator is sitting on the lid of the washer jar.
If there is no vacuum connection between the two, activation of the pushbutton will not "trigger" the coupler (via the coordinator)
The coupler physically turns on the motor (and turns it of after a preset time)

That's how I understand it

[Cadman-iac]

The coupler is the part on the motor  - the coordinator is sitting on the lid of the washer jar.
If there is no vacuum connection between the two, activation of the pushbutton will not "trigger" the coupler (via the coordinator)
The coupler physically turns on the motor (and turns it of after a preset time)

That's how I understand it

 I guess I better go read up on this system with the washers in it again then. My memory isn't as good as it used to be, and I've slept once or twice since I've messed with mine, which might account for my confusion, at least a little of it anyway.
 I will have to figure this out when I put it back in the car anyway.

[Cadman-iac]

  Ok, just from what I've found in a quick glance at the service manuals for 56 and 57, I can see where some confusion is possible. 
The 56 manual calls the part I have mounted to my wiper motor a coordinator, but in the 57 manual it's called a coupler. So it's basically just a terminology issue originating at GM because someone couldn't remember what they called a part the previous year.
The description on how to adjust either of these is identical, it's only the name of said part that is different.


This is out of the 57 service manual.


From 57 service manual.


From 56 service manual.


From 56 service manual.

The coordinator shown in the 56 manual looks different than the one I'm using. I honestly can't remember where mine came from, if it was on my parts car, or if I just used a Chevrolet one. The instruction sheet for the accessory washer unit for the Chevrolet shows one identical to what I've got.
 But the 56 Cadillac service manual shows the 1st design drive pulley mounting plate too, so I'm thinking that since both my car and parts car have the 2nd design drive pulley and mounting plate, that the coordinator design may have changed as well, especially since the 57 manual shows the same design coordinator/coupler as mine.

I'm still working out exactly how the coordinator/coupler works with the wiper control switch and cable. Not sure if it will actually move the cable in and out on the switch, or if it's just that little washer that slides back and forth on the cable itself.
I've gotta set everything up and turn it on and see what happens between the parts. May take a while, but I'll get back to you.

  Rick

[Cadman-iac]

  Alright, from what I can ascertain by setting up my motor and switch with the coordinator mounted on it, is that the wipers will come on after you engage the washer pump with the control switch button, which causes the coordinator to turn the motor on independent of the manual wiper control switch. The plunger in the coordinator moves the slider on the motor which turns it on.
Once the washer pump has cycled it turns off and in turn releases the vacuum to the coordinator which then retracts and turns off the wiper motor.
If you turn on the wipers with the manual control switch, the coordinator will move with the slide without turning on the washer pump.
The only way to get the washer pump to operate is by pressing the button down on the control switch. But this can be done with or without the control switch being rotated.

Now, since I've dug back into all this, I must say that in order to use the Chevrolet electric wiper motor, there are a few modifications that need to be made to the center drive mounting plate.
I had forgotten about this since I did it so long ago, but I did save the original parts from my car as backups just in case they were ever needed.
In comparing the two, I saw what I had done to be able to use the Chevy wiper motor.
Also, before we go any further, the original vacuum wiper motor sits up high, rotated above the mounting plate in order to clear the air cleaner assembly.
The electric wiper motor sits lower on the mounting plate and will interfere with your air filter housing. If the housing is anywhere near the motor mounting plate, then this Chevrolet motor will not work for you.
I had forgotten about this, and it didn't really matter in my case anyway because I'm using a 472 in my car and it sits a bit farther forward and I think the air filter housing clears the wiper motor due to its lower profile.

So unless you are willing to make other modifications to the car, don't try the Chevrolet wiper motor.
  I wish I had remembered all this before I suggested it to you, but this at least got me back into the system so I could explain what is necessary if you were going this route.
I'm sorry this isn't the solution you were looking/hoping for.

Your idea of using the original switch to activate the new switch may be your best option, but you will still need to buy the aftermarket system.


I also figured out why the Chevrolet motor operates opposite from the Cadillac motor. It's because the Cadillac vacuum wiper motor sits upside down. In the park position, the "piston" is at the other end of the motor versus the Chevrolet vacuum wiper motor, which mounts 180 degrees opposite from the Cadillac. This puts the piston, (or paddle), on the other side of the motor on the Chevrolet, so if you're using the Chevrolet electric wiper motor, it parks 180 degrees out.
Swapping the drive cables on the center drive pulley corrects this problem.
I hadn't researched this before because it really didn't matter to me at the time I was adapting the electric motor to my car. Now though, I can see why it's not just a bolt in.
  If there were enough room to mount the electric motor upside down it would work without swapping the cables, but unfortunately it hits the cowl just above the mounting plate.
If you're trying to figure this out in your head, just remember that the drive pulley doesn't rotate 360 degrees, it only moves about 120 degrees at most.
Look at it this way, if you were to remove the mounting screws for the vacuum motor while it's still in the park position, and you didn't disconnect it from the drive pulley itself, but simply rotated the motor 180 degrees and remount it like it was a Chevrolet motor, your wiper arms would be in the opposite end of their travel.
I just wanted to explain this for anyone who is thinking about using a Chevrolet motor on their Cadillac why it doesn't work without modifications.
I hope I have explained it clearly enough, and I hope I haven't forgotten anything.
If you wonder why I called it a "paddle" inside the vacuum motor, if you ever take one apart you'll understand.

Good luck Kurt, I hope you find a solution to your problem. If you have any other questions, feel free to ask, I'm happy to try to answer them. And hopefully I don't steer you wrong next time.

I'll post some pictures of what I've been referring to on all this soon.

  Rick

Edit: OK, here's some pictures of what was necessary to adapt a Chevrolet electric wiper motor into a 56 Cadillac. Probably the same thing would have to done for a 57 as well.


Both modified (L) and original (R) center drive mounting plate.


These two raised tabs had to be removed.


Had to drill a small relief to clear the rivet on the motor bracket.


This little alignment tab had to go too.


  Edit: I have more pictures to post of the differences between the Cadillac and Chevrolet systems, but the website is not letting me upload them. As soon as this is resolved I'll post the rest of them.

[J. Gomez]

Kurt,

If you want to change the wiper motor to an electric one (Newport one) and keeping the original slider cable switch to active the motor, you would need to rig a 3-pos slide switch inside a case so when you move the slider the cable will move the switch in-out.

I rigged a similar layout for my 1956 since I did not want to butcher the original dash switch and I've also keep the original washer pump (see attach pictures). This initial prototype rig worked fine with the original cable switch and the vacuum washer pump.

I had to drill a small hole on the switch plastic slider to insert the cable end (push) and made a collar around it to hold the small end washer (pull). Now the cable shield would need to be held securely at the case for the cable to slide in-out.

However, since them I've changed the system to all electric wiper and washer and re-did the dash control switch (had an extra one in stock) to function with the rotary switch for the motor and same push switch for the washer. In your case since your 1957 has the slider type switch that would be a bit more complicate to do a full conversion.

Hope this helps..!

[Cadman-iac]

  Great idea Jose. I must confess, I didn't realize that Cadillac had switched to a sliding wiper control switch for the 57. But the basic operation is still the same as the 56, it still moves a cable to turn on the wipers, and a button to activate the washers.

 Rick

[V63]

I'd like to meet the salesman who sold Cadillac with continued Vacuum wiper technology thru 1958  🤦🏻�♂️

Cadillac offered the most technical advanced automobile for $13,074 and it still had pathetic vacuum wipers.🙄🥴

[Roger Zimmermann]

Lincoln, as well as other brands, had vacuum wipers till the sixties!

[The Tassie Devil(le)]

The good thing about the Vacuum Wipers when new was that the speed was infinitesimally adjustable by slowly turning the knob that controlled the sliding of the slider valve.

Also, don't forget that when these cars were new, the wipers worked perfectly.   It is not their fault that that we are still using cars well beyond their "use-by-date".   New cars had good compression.

Plus, when we drove those cars, in most cases, they were driven at "Normal" speeds for their time.

Bruce.