How Your Headlight Vacuum System Works
#21
Le Mans Master
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C3 of Year Finalist (appearance mods) 2019
ok my headlights wont go down. if i remove one of the yellow stripe hoses from the tank and put my finger over the tank port the opposite headlight goes down. then do the other and they are both down. when lights are switched on they both come up very slowly. what could be my problem? thanks oh its a 1978.
Then test thr relays here: http://www.corvette-101.com/vacuum.htm#relay
Last edited by Peterbuilt; 12-08-2010 at 11:01 PM.
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redkenyan (01-28-2018)
#22
Test the actuators here: http://www.corvette-101.com/vacuum.htm#actuator
Then test thr relays here: http://www.corvette-101.com/vacuum.htm#relay
Then test thr relays here: http://www.corvette-101.com/vacuum.htm#relay
#24
I've posted it before but:
I used my shop vac instead of hand-pumping a mity vac. Works like a charm to pop-up the lights and pop them down(my motor was out of the car at the time)
I used my shop vac instead of hand-pumping a mity vac. Works like a charm to pop-up the lights and pop them down(my motor was out of the car at the time)
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Redbirdman (05-19-2019)
#29
Racer
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Update to .pdf File
Thanks again, all, for your kind comments and support.
I intend to maintain the .pdf file that is linked-to in the original post of this thread with updates, corrections, comments, and good stuff from posts on this thread and elsewhere. Click on that link and you'll always get the latest version.
Today's update adds vacuum reservoir tank test methods and tank locations description (from Mid America Motorworks), and a link to Willcox Corvette's “Headlamp Vacuum Hose Schematics 68-82”.
Jerry
78IndyPace
I intend to maintain the .pdf file that is linked-to in the original post of this thread with updates, corrections, comments, and good stuff from posts on this thread and elsewhere. Click on that link and you'll always get the latest version.
Today's update adds vacuum reservoir tank test methods and tank locations description (from Mid America Motorworks), and a link to Willcox Corvette's “Headlamp Vacuum Hose Schematics 68-82”.
Jerry
78IndyPace
#35
Instructor
I've just recently replaced all of the vacuum hoses. Now the lights go up and stay up. If I disconnect the hose that goes to the tank, they won't go up.
Anyone have any thoughts?
Anyone have any thoughts?
#36
Racer
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Good Luck!
Jerry
Last edited by 78IndyPace; 12-27-2010 at 09:48 AM. Reason: Added question by kirt8548 in quote.
#37
Burning Brakes
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Jerry, this is an excellent post. I recently completed the restoration of both of my pop-up headlight assemblies. I studied the mechanical linkages of the originals before I ripped apart and rebuilt them. But when it comes time to re-install them, plus run all of the vacuum lines - knowing how the system works will ensure that everything goes back together properly. You've done much to guarantee that this will happen. Many thanks.
#38
Jerry - Kudos for the great information and glad to see it is now a sticky.
I do have one suggestion - the title of the post should be
"How your headlight vacuum system is supposed to work".
I even put in a vacuum gage in place of my clock so I know when (not if) something is amiss in the vacuum system.
I do have one suggestion - the title of the post should be
"How your headlight vacuum system is supposed to work".
I even put in a vacuum gage in place of my clock so I know when (not if) something is amiss in the vacuum system.
#39
Burning Brakes
Awesome posts. On to-do list.
#40
Great post thanks so much
Jerry, I recently replaced all my vacuum lines and my headlights work great and so does the wiper door.....that is until about 5-10 minutes later the wiper door will raise. WTF
I have my car in the shop for re-painting but want to fix this as soon as it comes out. I was going to clamp of the vacuum supply to the wiper door and see if I can hold the door down. If this works I would move the clamp further from the door until I find the leak.
Do you think this will work or do you suggest a better method.
All the best and once again thanks.
I have my car in the shop for re-painting but want to fix this as soon as it comes out. I was going to clamp of the vacuum supply to the wiper door and see if I can hold the door down. If this works I would move the clamp further from the door until I find the leak.
Do you think this will work or do you suggest a better method.
All the best and once again thanks.