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1954 Buick Forum - the 54 Buick Highway

Windshield Washer Operation

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I'm looking for some education on how the windshield washer system works on my Special. 
Nothing was there when I bought the car. The fuel pump and wiper motor were in a parts box, the port on the manifold plugged off, and a little electric fuel pump supplying the carb. I installed an electric wiper motor when I figured out that the vac motor was in need of a rebuild.  Maybe a year and a half ago, I rebuilt and reinstalled the factory fuel pump but still have the electric fuel pump, though it is now wired to a switch and only used occasionally for priming purposes. I don't have any intention of putting the vac wiper motor back in at this time, but I'd like to be able to clean the windshield occasionally without pulling over to a service station. I just acquired a used washer bottle/pump and have messed around with it a little without a whole lot of success at this point. I want to figure out what my issue is before I spend $80 on a washer pump rebuild kit if it's not really the problem. 
First, I need to determine if my "switch"/controller is operating correctly. I dug through my parts boxes and was able to find the rigid line that runs from the vac side of the pump back to the firewall. So I ran a new vac hose through the firewall and over to my wiper switch/controller, then from the switch out to the bottle location on the air box. When I start the car, I have vacuum at the bottle end of the hose without pressing the button in the center of the controller. When I do press the button, there is still vacuum at the bottle end of the hose, but noticeably less, and I can hear it sucking air in at the controller/switch inside the car, presumably around the shaft. I can't find any real information about how this "switch" operates, so I don't know if this is normal. If normal, this means that vacuum is pulled on the washer bottle siphon pump through the switch at all times when engine is running until the button is pressed, essentially creating a vacuum leak. Can anybody confirm if this is how the controller operates, or is there a problem with it that I need to sort out?
I have questions about the bottle pump/siphon tube operation as well, but I'll hold off until I know my controller is working properly first.

Wiper Washer Control Switch.JPG

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Funny, I was just farting with this lately...  You have to remove the switch from the dash, no way around it, to clean and seal it up again.  The shorter tube on the unit goes to the vacuum source, the longer one to the pump.  

First, undo the headlight switch from the dash, and it will set to the side without removing any wiring.  It will lay off to the side, just enough.

To remove the wiper/washer control, disconnect the cable at the wiper motor, and feed it back under the dash.  I connected the loose end to a piece of vacuum hose so as to keep the original routing around and under the dash.  At the switch, first to come off is the turn knob which pulls off with some effort.  I used vice grips wrapped in tape, and grabbed at the elbow that hangs down, closest to the center button.  Pull firmly, and it will slide off.

Now you will find the spanner nut like on the headlight switch.  Needle nose pliers got mine undone. 

To rebuild the vacuum switch, use a magnetic tray and work over that.  Two small machine screws take therear piece off that contains the valve, and there are ttwo small disks, a pin, and a spring - all easily lost.  Basically, clean it up, lube the disks with heavy grease to help them seal, and use light gasket sealer onboth sides of the gasket.  Mine now holds a good vacuum - much better than before.

Vacuum via the shorter tube is held in the end-most chamber by a disk and spring.  When the button is pushed, it pushes the inner disk and pin, opening up the outer disk and spring to allow vacuum to flow through the longer tube.  And that actuated the washer motor.  With the button not pressed, the shorter tube is supposed to hold vacuum.

On the washer pump, I have a rebuild kit from years ago that some day I will use from McVeigh Cadillac or something like that.  They look simple, just be careful of the plastic housing.  The larger chamber is vacuum, the smaller for fluid, and inside is a spring-loaded dual piston.  Vacuum pulls the piston up against the spring and that action draws washer fluid into the lower chamber by displacement.  When the piston reaches the top, a vacuum release is opened, and the spring takes over, pushing the dual piston back down and sending fluid to the washer nozzles.

Part of the project will likely involve replacing all rubber lines.  Plan on removing the upper dash and the radio to get to the old lines and route them per original.  Nothing complicated, but at PIA.  Use compressed air to be sure the hard lines at the wiper arm base are free to flow.

Happy wrenching!


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On 12/3/2019 at 2:18 PM, Vindictive said:

but I'd like to be able to clean the windshield occasionally without pulling over to a service station

I have the system working on my cars.  While it is neat to have it functioning as designed, that pathetic squirt is essentially useless.

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It was pretty crusty in there. Looked like dried up old lithium grease that wouldn't allow the discs to seat properly on the sealing surfaces down inside the body. Used a high tech pencil eraser with a little piece of 800 grit sand paper stuck to the end to get down in there and get at those surfaces. Cleaned everything up real good and greased the discs.  Seems to be holding vacuum well. Will get it back in the car and see what happens.







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