73 headlight question
Thread Starter
Instructor
Joined: Mar 2005
Posts: 166
Likes: 0
From: Byhalia MS
73 headlight question
I am working on trying to get the headlihts on my 73 to work properly. I bought a new vacuum kit to install and the instructions are pretty self explanatory. The question I have, is how do I test the headlight actuators to be sure they have vacuum, and the "holes" in the vacuum tank that the instructions refer to be sure they aren't clogged.
thanks Al
thanks Al
Team Owner
Joined: Sep 2006
Posts: 31,274
Likes: 4,366
From: Westminster Maryland
Hi Al,
You need a vacuum pump like a Mity-Vac in order to test the actuators.
Disconnect the large GREEN striped hose and attach the vacuum pump. If the vacuum holds, the internal diaphragm is good. If the vacuum pressure drops the internal diaphragm is leaking and the actuator needs to be rebuilt or replaced.
Disconnect the large RED striped hose and attach the vacuum pump. If the vacuum pressure holds, the internal diaphragm and rear sealing grommet are both good. If the vacuum pressure drops during this check, but was held in the GREEN striped hose check, only the rear sealing grommet is leaking and can be replaced.
Good Luck!
Regards,
Alan
You need a vacuum pump like a Mity-Vac in order to test the actuators.
Disconnect the large GREEN striped hose and attach the vacuum pump. If the vacuum holds, the internal diaphragm is good. If the vacuum pressure drops the internal diaphragm is leaking and the actuator needs to be rebuilt or replaced.
Disconnect the large RED striped hose and attach the vacuum pump. If the vacuum pressure holds, the internal diaphragm and rear sealing grommet are both good. If the vacuum pressure drops during this check, but was held in the GREEN striped hose check, only the rear sealing grommet is leaking and can be replaced.
Good Luck!
Regards,
Alan
Race Director
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Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
http://www.corvette-101.com/vacuum.htm
This paragraph is from the above link. Anyone see a problem with the general function test ?
GENERAL FUNCTION TEST
The headlamps should be off and closed and the pull down switch should be pushed in. Pinch closed the small white hose leading to a relay valve and the headlamp doors should open. When released, the door should close. This operation usually can only be performed once without the car running. If this test fails and your headlamps still open and close while the car is running, it simply means the system is not operating at 100 percent as designed. The following tests should help you pinpoint why this test failed.
This paragraph is from the above link. Anyone see a problem with the general function test ?
GENERAL FUNCTION TEST
The headlamps should be off and closed and the pull down switch should be pushed in. Pinch closed the small white hose leading to a relay valve and the headlamp doors should open. When released, the door should close. This operation usually can only be performed once without the car running. If this test fails and your headlamps still open and close while the car is running, it simply means the system is not operating at 100 percent as designed. The following tests should help you pinpoint why this test failed.
Thread Starter
Instructor
Joined: Mar 2005
Posts: 166
Likes: 0
From: Byhalia MS
headlight question
started trying to resolve the problem based on the outstanding responses recieved. The test regarding actuators: My headlights are "stuck" in the up position. On or off by the headlight switch they stay up. How do I get the headlights to go down to perofrm the tests to determine if the head light actuators are working. Tried pushing them doen, but will not go. Don't wont to force them and break something.
Please help
Please help
Drifting
Joined: Jul 2004
Posts: 1,556
Likes: 91
From: Skiatook. Oklahoma.
I disconnect the vacuum lines from the actuators. I then reach up into the fresh air openings under the front of the Corvette. Feel for the support arm for the headlight assembly and pull down enough to release the overcenter lock. They'll close right up.Be careful not to grab the switch's that are mounted on the arm's,they'll break off easily.
Marty.
Marty.
Last edited by orourke; Oct 15, 2010 at 04:01 AM.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
started trying to resolve the problem based on the outstanding responses recieved. The test regarding actuators: My headlights are "stuck" in the up position. On or off by the headlight switch they stay up. How do I get the headlights to go down to perofrm the tests to determine if the head light actuators are working. Tried pushing them doen, but will not go. Don't wont to force them and break something.
Please help
Please help
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Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
http://www.corvette-101.com/vacuum.htm
This paragraph is from the above link. Anyone see a problem with the general function test ?
GENERAL FUNCTION TEST
The headlamps should be off and closed and the pull down switch should be pushed in. Pinch closed the small white hose leading to a relay valve and the headlamp doors should open. When released, the door should close. This operation usually can only be performed once without the car running. If this test fails and your headlamps still open and close while the car is running, it simply means the system is not operating at 100 percent as designed. The following tests should help you pinpoint why this test failed.
This paragraph is from the above link. Anyone see a problem with the general function test ?
GENERAL FUNCTION TEST
The headlamps should be off and closed and the pull down switch should be pushed in. Pinch closed the small white hose leading to a relay valve and the headlamp doors should open. When released, the door should close. This operation usually can only be performed once without the car running. If this test fails and your headlamps still open and close while the car is running, it simply means the system is not operating at 100 percent as designed. The following tests should help you pinpoint why this test failed.
.If what is said in red above was to happen the diaphragm in the relay would be BAD.
I am not a fan of that sight.
I have not read the entire thing because there are too many mistakes starting on the first page 
. The vacuum diagram is wrong and the general function test is flawed. Does anyone know who the PUTZ was that wrote that ?