Can anyone explain exactly how the vacuum wipers work on a 57?

[JC316]

Hi guys, I have a 1957 Coupe Deville and I have a question regarding the windshield wipers. When vacuum is applied via the switch or an electric pump, the wipers move outward, but they don't return until vacuum is released. How exactly are they supposed to return? Is there a vacuum release somewhere in the motor, or does the motor spin in one direction while something slips in the assembly? I've checked the manual and the internet, but am coming up empty.

D. Winchester.

[dn010]

Your question is not limited to the 1957, most of these all work the same way. I just rebuild my vacuum motor, it is kind of difficult to explain in text without photos. But basically, picture the vacuum motor as half a circle. In the middle is a paddle that divides the half circle in half again which are two chambers. When you apply vacuum via the switch, the vacuum goes into one chamber sucking the paddle one way, and there is a switch that when the paddle gets to the end of travel, it switches the vacuum to the other chamber which pulls the paddle the other direction, thus making your wipers swipe. When the wipers are switched "off", vacuum is applied to the one chamber that "parks" the wipers. there is a seal on the paddle that seals against the top of the vacuum motor in the full park position and keeps it there until you switch the wipers on again, sending vacuum to the other chamber to move the wipers.

The switch inside the car moves a sliding rubber/plastic long rectangular part on the wiper motor that has holes and passages to direct vacuum where it is needed. I'd surmise your issue is with that sliding rectangular part, or the switch directing the vacuum to the other chamber when it needs to change direction.

I will try to get some photos for you to assist in explaining this.

[dn010]

I do not know if these help of complicate matters, but here are some photos to help explain the above.





 

[JC316]

Your question is not limited to the 1957, most of these all work the same way. I just rebuild my vacuum motor, it is kind of difficult to explain in text without photos. But basically, picture the vacuum motor as half a circle. In the middle is a paddle that divides the half circle in half again which are two chambers. When you apply vacuum via the switch, the vacuum goes into one chamber sucking the paddle one way, and there is a switch that when the paddle gets to the end of travel, it switches the vacuum to the other chamber which pulls the paddle the other direction, thus making your wipers swipe. When the wipers are switched "off", vacuum is applied to the one chamber that "parks" the wipers. there is a seal on the paddle that seals against the top of the vacuum motor in the full park position and keeps it there until you switch the wipers on again, sending vacuum to the other chamber to move the wipers.

The switch inside the car moves a sliding rubber/plastic long rectangular part on the wiper motor that has holes and passages to direct vacuum where it is needed. I'd surmise your issue is with that sliding rectangular part, or the switch directing the vacuum to the other chamber when it needs to change direction.

I will try to get some photos for you to assist in explaining this.

Perfect. That tells me exactly what I needed to know. I am probably going with the electric motor retrofit anyway, but I was worried that there might be something wrong with the cable assembly. Thanks so much for the help.

[dn010]

Nope, if it goes one direction and parks itself, your cables are fine, could probably use some lube but it is working. Electric motor is more modern, more powerful and far less problematic; I just didn't go that route because I don't drive in the rain, nor did I want to deal with running a new switch and wiring for the electric motor.

https://newportwipers.com/product/1954-58-cadillac/#wiper-motor

[Nickl]

I do not know if these help of complicate matters, but here are some photos to help explain the above.





 

Wanted to know if there's a shop who sells rebuilt kits for this old trico wiper motors.
Wanted to rebuilt mine of a 54.
Thank you

[V63]

Vacuum wipers work best when it's not raining 🙄, good move going electric, but be mindful the 57 Chevrolet electrics require the cables be reversed so they 'park'

[Dave Ventresca]

this is the site for trico wiper repair. www.wiperman.com
I have had several motors rebuilt by them. Dave

[Nickl]

this is the site for trico wiper repair. www.wiperman.com
I have had several motors rebuilt by them. Dave

I know the site but want to buy a rebuilt kit and do the work by my self

[Cadillac Jack 82]

I know my 57 was a pain in the a**.  Wipers worked okay but would never fully go into Park mode.

[dn010]

My wipers work so-so but nothing as great as electric. I do not know of anyone selling rebuild kits outright. You can get gaskets on ebay and sometimes a rebuild kit that has limited parts however I have never been able to find anything to rebuild the paddle with - no write ups about what material to use, no replacement material etc. I have no idea what the re-builders use and they seem to keep it quiet for good reason. In the end, I had to buy a "parts" paddle from a different model car, open up the paddle and transplant the correct 1957 Cadillac shaft into it in order for it to work.

[Caddy Wizard]

The smart-aleck in me would simply reply "not well".  But the main idea is that vacuum pulls the paddle one way to move the wipers in a first direction.  When it gets to the end of the travel, the vacuum is applied to the opposite side of the paddle, pulling the wipers back.  The power comes from the size (surface area) of the paddle being exposed to the vacuum.  So, for example, if the paddle is 4 square inches and the vacuum is about 5psi below atmospheric pressure, you might get 20 pounds of force pulling on the paddle. That gets turned into a twisting force to rock the wiper arms back and forth.

Normally, the best thing to do with these is send the wiper motor assembly out to be rebuilt.  That is normally better than trying to do it oneself.  As noted by others, the place to use is "wiperman" (Ficken Wiper Service).

Ficken Wiper Service

631-587-3332 M-F 9-5 Eastern Time
sales@wiperman.com

[fishnjim]

FYI: I'm hearing that Ficken is not so good anymore and doesn't sell parts.  There was some change in the website also as they lost their name to another site.
The old man died and the kid is running it.  Check the internet comments in AACA, etc. or other brand sites.  Apparently was at Hershey, too.
This will be a lingering issue, as trico has not made these for many decades and parts are unobtainium.   I switched to electric as soon as I got the '58.
If you survived the vacuum wiper era, you'd know why.
This will need some research to find out some answers.   I hadn't found any parts lists or catalogues in my many searches, so if someone has the info, pass it on.
ps: I know there was another post on this same issue, and this one is old.

[dn010]

There's really only 2 main parts that can go bad rendering the motor inop.

1 - the biggest issue is the paddle. The material is so old now that it cracks easily. Original material is some sort of very thin rubberized material that was either vacuum formed or heat formed to shape - don't know what repair companies are using to replace this with. (If I did, I'd be in business too!). Once you get a crack or a chunk falls out, vacuum bypasses the paddle and your motor is dead.

2 - the park seal - easy replaceable using a 1/32 or similar sheet of rubber cut down to size and riveted on. If your wipers work but won't park easily, the seal is bad and leaks vacuum - won't pull the paddle all the way into park position.

The top and side cover gaskets can be cut (I cut mine from a sheet of felpro fiber gasket material). Can get the gaskets on ebay too.

The motor body can be soaked/cleaned up and greased, the filter cleaned and if you have 1-2, it can go back together (the paddle uses a lot of grease packed inside of it). I put a thin coat of grease on the sliding activation switch on the motor. If the rest of your wiper system is not up to par - no lube on the wiper posts/transmission, cables (transmission cable AND activating lever cable) then a rebuilt motor won't do much for you.

As stated, don't expect electric wiper quality from the vacuum wiper system. I'd even take the hydraulic (power steering) wiper system I used to have on my 1966 other brand vehicle over vacuum!