Vacuum Wiper Motor help

[willits]

I am hoping that there might be someone versed in Trico vacuum motors out there who might be able to help with an issue I am having with the wiper motor on my ’58.  I took the motor out of the car dissembled it, cleaned it and reassembled it.  This was because of some binding on the switch, vacuum valve.   Prior to the binding it was working as good as it ever did.

The issue is that I am not getting full right to left movement when I bench test the motor.   I can see that there is a piston in the housing on the top of the motor that lifts the cam, (red arrow pointing at it in the picture) which allows a greater arc of rotation when the piston is under vacuum.   This apparently is not working.   I checked that the passages are clear and nothing is blocked.  That part looks to be fine.

I am fairly sure that I got all the parts back in the correct locations.   

The only thing I can think of is that maybe the felt air filter, (the blue arrow), is blocking the air flow into the motor and there is not enough flow to move the piston.    Other than that I am at a loss, any ideas out there?   

Thanks,
Peter

[Jay Friedman]

Rather than try to fix it yourself, I suggest you send it to www.wiperman.com.  He charges $99 + $8 for shipping to rebuild a Trico motor.  He is really good and did my '49's vacuum ww motor a few years.  It performs as well as electric wipers.

[Walter Youshock]

I agree.  Send it out.  Worth the money just to have it done right or send it back.

Don't forget the vacuum manifold on the cowl.  Nobody rebuilds those so you'll have to let it go or try to replace the gasket inside it yourself.

[willits]

Thanks for the advice and the wiperman contact.  I may go down that route.

Walter â€" I did put new rubber in the vacuum manifold just last year.   

In the meantime I have changed my opinion on this problem.   

Before I took the motor apart and cleaned it I would something like 120 degrees of travel, (from the parked position to just past where the windshield starts to curve). 

Now I get around 80 degrees of travel, (it is easier to see on the video â€" link below). 

So I am thinking that they had too much travel before and are now actually are operating correctly. 

Any thoughts? 

Thanks, 
Peter

Wiper & motor  Video:
https://plus.google.com/photos/113898381826791809458/albums/6115263363090369457?authkey=CLOOp7aYlfmQjwEhttps://plus.google.com/photos/113898381826791809458/albums/6115263363090369457?authkey=CLOOp7aYlfmQjwE

[Walter Youshock]

Did you mess with the wiper arms, wiper transmission alignment or cable tension?  It's important that all these factors are checked.  If the wipers aren't aligned for the windshield and the wiper cams aren't right,  it'll make you crazy.  The passenger wiper on my car would walk off the cam and basically fall off the car.  This was a regular problem with these cars.  I know a few owners who lost passenger wiper arms and damaged windshields.

Check the alignment procedure in the '57 shop manual.  Your wipers might be binding slightly.

Btw:  you'll need an assistant if you plan to loosen the cable tension and reset the transmissions.

[Jon S]

Thanks for the advice and the wiperman contact.  I may go down that route.

Walter â€" I did put new rubber in the vacuum manifold just last year.   

In the meantime I have changed my opinion on this problem.   

Before I took the motor apart and cleaned it I would something like 120 degrees of travel, (from the parked position to just past where the windshield starts to curve). 

Now I get around 80 degrees of travel, (it is easier to see on the video â€" link below). 

So I am thinking that they had too much travel before and are now actually are operating correctly. 

Any thoughts? 

Thanks, 
Peter

Wiper & motor  Video:
https://plus.google.com/photos/113898381826791809458/albums/6115263363090369457?authkey=CLOOp7aYlfmQjwEhttps://plus.google.com/photos/113898381826791809458/albums/6115263363090369457?authkey=CLOOp7aYlfmQjwE

They should travel much further than your video shows.  All the way to the bottom and just past the cuve in the windshield.  that is why the arm are cam-o-matic to account for the windshield curvature.

They also seem very slow - straining . . .

[Walter Youshock]

On high speed, they shouldn't go to the extremes of the windshield.   On low speed,  they should act as Jon said.

One other factor is the washer.  It can cause a vacuum leak.  Try plugging the washer source and eliminate vacuum leaks one at a time.  I still think it could be your motor.

To be honest,  when properly working, the vacuum wipers aren't all that bad.  I've been caught in storms and they do work well. 

Lincoln continued with vacuum wipers well into the early '60's.   

[Jon S]

Walter is correct - I've only used my wipers twice, but they perform very well even accelerating up 20 degree hills!

[Walter Youshock]

Only twice in all the years this car has been in the family?   I use mine at least 3 times a year.   

Honestly,  I check the operation almost every time I wash the car.  There's something edifying with the unbelievable silence of vacuum wipers. 

It's part of the charm of these cars.  My dad disagrees.  He always said they sucked and blew when new. 

[Jon S]

Only teice. This was originally a Sunday car and never out in wet weather.

[willits]

Well this is actually encouraging. 

I do use wipers a normal amount.  We do antique car rallies and go regardless of the weather.  We tend to be the longest and heaviest of the participants, but hey it’s a Cadillac what else would you expect.   

Up hills the wipers have always stopped or barely moved.  Running down the road they are a little faster than the video but not much.  It was about 28 degrees out when I took the video so I chalked the slowness up to the cold.   It has warmed up to a balmy 36 so it might be better to test today. 

I will be checking the cable tension, make sure there is no binding and that the vacuum is good and work from there.  They never have run very fast in the 30+ years I have had the car, but that doesn’t really mean anything since I always accepted that they were as  good as they ever were going to be and I’ve not done much with them.   

I did change the vacuum pump some years ago and I get a sort of jiggly vacuum reading between 19 and 21” hg.   

Last year I redid the rubber flapper valves on the vacuum manifold on the firewall.   

I will report back on my progress. 

Peter

[Jon S]

Peter -

Watch this video - this is how the wipers should work (dumb to do it on a dry windshield).

https://www.youtube.com/watch?v=xD-eWRhO1GM

[35-709]

Here is another way to go unless your '58 must be kept original ---

http://www.newportwipers.com/products.php?year=1954-58&make_id=8

[willits]

Well after a few more tries I now get the longer arc at slow and shorter at fast but still no speed.

I thought about he electric conversion, but they are really not all that well thought out.   The switch would have to be hidden some where and I would not have a squirters.   
   
So I have gone back to the first suggestion and am getting a rebuilt motor from Rob at wiperman.com.   Hopefully in a few weeks I can share a video of mine working as well as the Coupe in the video Jon shared but with a wet windsheild. 

Peter

[cadman49]

willits..I don't know exactly about the 58,but my 57 has another vacuum pump in the oil pan!!! I know,its crazy but true. its driven by the oil pump. I think the main idea was it doesn't depend on engine vacuum on keeps working at any engine speed, so when your wipers run out of wind this one keeps on sucking vacuum. its hooked to a fitting on the pass side at the rear of block. a hose from there goes up to a little 3 port manifold on the cowl. there's 2 at the bottom. one port to carb or manifold,the other to the pump in the pan the 3rd one (top) goes to the wiper motor. the little flapper valve inside decides whos got the most vacuum then routes to the wipers. pretty clever huh?  Cadillac didn't want any failure or noise. gotta admit pretty clever engineering!! buick also had this.

[Walter Youshock]

You're theory is close.  The vacuum pump was used on the 365 from '56 through '58.  That vacuum manifold on the cowl where all the hoses hook up to has 2 spring-loaded rubber valves.  At idle, the wipers work off engine vacuum.  As rpms increase, so does the speed and suction of the pump.  As engine vacuum drops under load, that manifold valve closes but the pump side opens to provide constant power to the wipers.

Never really understand why Chevy and Pontiac had electric wipers and cadillac stuck to vacuum...

[Roger Zimmermann]

  The vacuum pump was used on the 365 from '56 through '58.  That vacuum manifold on the cowl where all the hoses hook up to has 2 spring-loaded rubber valves.

Sorry Walter, the vacuum pump was used from 1954 to 1958. Buick had this system too.

[Walter Youshock]

I wasn't sure what year they started using it.  I knew it was all the 365 engines.  It's really more of a booster than anything.