72 wiper door

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Jan 1, 2011 | 02:19 AM

riverracer au

Thread Starter

Melting Slicks

Joined: Oct 2010

Posts: 2,276

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From: "ɹǝpunuʍop", Adelaide, South Australia

72 wiper door

with my engine off my wiper door sits about 3/4" up
when i start the engine it sits back down flush
is this mechanical or a vacuum problem, where do i look?
is it the actuator adjustment, relay, switch or something else?
it has just started doing this, but i have not touched or changed anything near there.

thanks

Jan 1, 2011 | 10:04 AM

Alan 71

Team Owner

Joined: Sep 2006

Posts: 31,198

Likes: 4,287

From: Westminster Maryland

Hi rr,
I think it's most likely a vacuum problem.
I'd say the relay that signals the door's actuator to open or close is leaking from the 'close' side of the relay while the car sits. When you start the car the vacuum is restored, the 'close' signal is restored, and the door closes.
Take a look at the second 'sticky' on the top of this page. A wonderful piece of work!
Happy New Year!
Regards,
Alan

Last edited by Alan 71; Jan 1, 2011 at 10:09 AM.

Jan 1, 2011 | 10:41 AM

riverracer au

Thread Starter

Melting Slicks

Joined: Oct 2010

Posts: 2,276

Likes: 337

From: "ɹǝpunuʍop", Adelaide, South Australia

will pull 1 of the headlight relays and swap it to give it a try/test on the door
will see if that makes a difference to the door or headlight

thanks
and a happy new year to you

Last edited by riverracer au; Jan 1, 2011 at 10:43 AM.

Jan 1, 2011 | 11:29 AM

Alan 71

Team Owner

Joined: Sep 2006

Posts: 31,198

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From: Westminster Maryland

Hi rr,
You can't swap the relays because the relay is designed to signal either wiper door vacuum or headlight door vacuum!
Regards,
Alan

Joke.

Jan 1, 2011 | 11:46 AM

Hammerhead Fred

Melting Slicks

Joined: Mar 2005

Posts: 2,093

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From: Midlothian VA

Quote:

Originally Posted by riverracer au

So, when the motor is running the door is pulled down flush but sometime after you cut the car off the door rises up a bit from flush until next time you start the engine (if I understand your description correctly).

Usually; this indicates a weak or defective vacuum check valve . (valve shown at link and Zip provides a nice diagram on the lower right of the page to help you locate it on your vehicle)

This part is easy to test before you go digging into all other possibilities. Simply pull the valve off hoses and check that it passes air/vacuum in only one direction. (if you clean it well you can do this simply by sucking air through it). If you can draw air/vacuum in one direction but not in the other it's good.

Last edited by Hammerhead Fred; Jan 1, 2011 at 11:50 AM.

Jan 1, 2011 | 06:56 PM

...Roger...

Race Director

Joined: May 2006

Posts: 16,528

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From: Dayton, Ohio

3/4" up ? The door is usually either up or down.
If you gently push the door back down with the engine off will it stay there ? If it will follow what the others have said.

If it won't stay down then I would be looking at a mechanical problem.
If the actuator was maladjusted but the system held good vacuum the door would stay down,however when the system developed a leak the maladjustment shows up.
The door with no hoses attached to the actuator should stay either up or down.

Jan 12, 2011 | 07:42 AM

riverracer au

Thread Starter

Melting Slicks

Joined: Oct 2010

Posts: 2,276

Likes: 337

From: "ɹǝpunuʍop", Adelaide, South Australia

update;
pulled the relay from fender
blocked the bottom port (green), vacuumed middle port (yellow), leaked air
un-crimped the top housing and pulled apart
placed 2 small 'o'rings in the ends of the piston with silastic
lubed piston with silicone grease, light smear on diaphragm
the hardest part was re-crimping the top back on, not pretty to look at
re-tested, ok, replaced back in car

wiper door has not moved up since i switched off engine 3 days ago

needs slight adjustment to sit exactly right when closed at one end

all learned from this wonderful forum

Jan 12, 2011 | 01:03 PM

Alan 71

Team Owner

Joined: Sep 2006

Posts: 31,198

Likes: 4,287

From: Westminster Maryland

Hi rr au,
Well done!!!
Headlight door and wiper door problems CAN be fixed without resorting to "I bought all new parts and it still doesn't work"!
Regards,
Alan