My windshield wipers

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Milsurp
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My windshield wipers

Post by Milsurp »

They work fine and all but, when I shut my vehicle off, the driver's side wiper will fall down about four or five inches. And when I start it back up the wiper returns wuickly to the full up position, No biggy really, just wondering why this happens.

Also, while driving along I am unable to manually work the wipers. They just won't move! However, if I pull the knob out they work on thier own just fine.

Can anybody explain these symptoms?
Lifer
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Post by Lifer »

Like you said...it's no biggie, teally. What's happening is that the grease inside your wiper motor housing has dried out "a bit" after all these years and is letting air by the flapper. The weight of the arm/blade overcomes the friction of the internals, and gravity takes hold of the wiper blade. When you start the engine again, the vacuum overcomes the effects of gravity and sucks it back up.

Either that, or there's one of these guys ( :twisted: ) just trying to see if he can get you frustrated.
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m-37Bruce
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Re: My windshield wipers

Post by m-37Bruce »

Milsurp wrote:
Also, while driving along I am unable to manually work the wipers. They just won't move! However, if I pull the knob out they work on thier own just fine.

Can anybody explain these symptoms?
I think Lifer answered the first part on target, however he neglected the 2nd ?, unless the grease answer works on both parts?
I think if you have enough compression for the wipers to work, it should hold it in the park position.
I also find it hard to believe that the wiper works, but not manually. Have you done a consultation w/ www.wiperman.com yet?
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Paul in Kempner, TX
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Question 2

Post by Paul in Kempner, TX »

To clarify M-37Bruce's comments...

When the motor is running and the vacuum valve on the wiper is in the "OFF" position, engine vacuum moves the wiper blades to the park position and then HOLDS them there.

The hand levers are designed to ASSIST the wiper motors when the vacuum valve is in the "ON" position. If you try to operate them by hand with the motor running, you are actually forcing the motor against the vacuum. This could lead to damage.

If you want to move the wiper blades by hand with the motor running, you will have to disconnect the vacuum lines from the wiper motors to allow atmospheric air to enter the motor housing. You will feel suction at the vacuum line fitting on the wiper motor.
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m-37Bruce
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Also

Post by m-37Bruce »

They should move freely w/the motor off, ie; not running. If you have them in another position, other than Park, when you start your engine, they should move to the Park position. Right Paul?
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Paul in Kempner, TX
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Not clear on VALVE or wiper position

Post by Paul in Kempner, TX »

If the wiper vacuum valve is OFF, the wipers move to the PARK position from any position they may be when there is a source of vacuum (engine running). It is possible that the PARK feature has been damaged so this is conditionally correct.

If the wiper vacuum valve is in any position other than OFF, they are ON and the wipers will move as best they can in wiping mode when there is a source of vacuum.

One of the first things you screw up when you take a vacuum wiper motor apart is the valve that controls wiper oscillation and the park feature. The wiper motor is not a space age invention, but little springs and check balls usually go into orbit when you remove the cover.

Vacuum wipers were the norm back in the fifties when I was first driving. An old mechanic's trick was to suck kerosene through the wiper motors to clean and lubricate them. You have to remove the motor, place it in a pan of kerosene so that the inlet is covered, and connect to a vacuum line that has a source of vacuum. Turn the valve to the on position. It is a good idea to have a catch jar for the dirty kerosene that has been sucked through the wiper motor. This must not be overdone. Having a catch jar lets you see when the dirt is gone. A small amount of kerosene sucked into the manifold is okay, but none is better. Kerosene has a residual lubrication that works in all seasons. Almost any grease is temperature sensitive. Use kerosene because most solvents dilute any lubrication.
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Post by Lifer »

Type-A auto trans fluid also works well to soften up the grease and lube the moving parts and has a higher flash point than kerosene. Mind you, neither one is a permanent fix, but my '55 Pontiac wipers still work great after I sucked a bit of ATF through it 10 years ago. (They either worked very slowly or didn't work at all before I did it.)
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