Vacuum/Headlight problem, Need help.
Thread Starter
Racer
Joined: Apr 2001
Posts: 413
Likes: 0
From: Bluffdale Utah
Vacuum/Headlight problem, Need help.
Okay. I haven't opened the headlight doors for more than a year. Last year I replaced the L48 with the ZZ4. Anyhow, lately I've been fumbling with the hoses to make sure they are attached correctly and testing for vacuum leaks with a pump. I thought I finally got it today, started the car and let it warm for a couple minutes, pulled the lights on and.....nothing. I got out, leaving it running, and pulled the lights up and they stayed until I shut the lights off. Seems there is some vacuum there, but not enough to open them without manual assist. Like I said, I checked for leaks and found none. What might be wrong? I haven't checked the engine vacuum yet, but I'd suspect it should be sufficient. Thanks in advance to my friends here.
Burning Brakes
Joined: Aug 2001
Posts: 854
Likes: 7
From: dudley ma
Re: Vacuum/Headlight problem, Need help. (1980ZZ4)
check out Covette Magazine from corvette forum homepage they just did a couple of articles on headlights parts that need to be replaced to fix various problems
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: Vacuum/Headlight problem, Need help. (1980ZZ4)
Actuator seals, commonly known as the 'witches hat' are available through many parts houses....about 15 bux each.....
remove hood to avoid scratches, mark hinges carefully with scratch awl for reinstall.....
remove pins on actuator rods to mechanisms...., remove 4 bolts each actuator...
outer accordian rubber is a dust seal....
inner witches hat comes off in the obvious fashion....you need mark the rod length for reassembly.... I use a dab of RTV for assemble to preclude any air leaks....that metal clamp holding hat on actuator is not that severely needed if you use RTV, so if a tab breaks off....forgetaboutit....
GENE
remove hood to avoid scratches, mark hinges carefully with scratch awl for reinstall.....
remove pins on actuator rods to mechanisms...., remove 4 bolts each actuator...
outer accordian rubber is a dust seal....
inner witches hat comes off in the obvious fashion....you need mark the rod length for reassembly.... I use a dab of RTV for assemble to preclude any air leaks....that metal clamp holding hat on actuator is not that severely needed if you use RTV, so if a tab breaks off....forgetaboutit....
GENE
Melting Slicks
Joined: Mar 2001
Posts: 3,365
Likes: 5
From: Lake Villa IL
Cruise-In IV Veteran
Cruise-In V Veteran
St. Jude Contributor
Re: Vacuum/Headlight problem, Need help. (1980ZZ4)
Don't discount the actuators. The rubber grommets and whatnot could have a crack. But first, check the vacuum at the actuators themselves. If you're getting vacuum there, then you can safely assume the actuators are the culprit. If you're not, check the lines for leaks.
Go to Corvettefaq.com and look up the headlight section. There is a great paper there that will walk you through the whole thing.
Go to Corvettefaq.com and look up the headlight section. There is a great paper there that will walk you through the whole thing.
Racer
Joined: Jan 2001
Posts: 495
Likes: 0
From: ma
Re: Vacuum/Headlight problem, Need help. (joeveto)
There are too many places for leaks to ocur on these cars. First get yourself a good vacuum gage and test every componant seperatly.Those hand pump brake bleeder are great to test everything from your vacuum tank to diaframs.Lots of leaks are a combination of little leaks that can make finding them very difficult
Thread Starter
Racer
Joined: Apr 2001
Posts: 413
Likes: 0
From: Bluffdale Utah
Re: Vacuum/Headlight problem, Need help. (1980ZZ4)
Thanks for all the replies so far. To answer most of them in this one reply, I pulled the signal hose that runs between and connects the actuators, pumped the vacuum up to 20 lbs and it didn't bleed anything for the two minutes I left the vacuum connected. I've also checked the vacuum on the reserve canister (Coffee Can). Is it possible the actuators could still be a problem? One thing I didn't mention in my original question is that when I pull the light switch on, the lights do make an attempt to open. I don't know if this condition could exist, but I was wondering if there are helper springs, like those for your garage door, that might have weakened over time. I'm continuing to check out things that might be replaced to help the condition. Please continue to provide your advice as you think of new possibilities. I give the majority of you credit for knowing more than I do and appreciate all your input. Thanks again!
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Melting Slicks
Joined: Nov 2000
Posts: 2,663
Likes: 3
From: Palm Harbor FL
Re: Vacuum/Headlight problem, Need help. (1980ZZ4)
[QUOTE]One thing I didn't mention in my original question is that when I pull the light switch on, the lights do make an attempt to open. QUOTE]
This is exactly what mine did. The fact that they make an attempt tell you two things: 1) That there is vaccum getting to the actuators and 2) that your relays are working. Both times this happend to me, it was the acuator seal. You can buy the kits form Eckler's or any of the Vette places but they're not particularly cheap (as most old Vette parts are not). It's like $24 for a couple of rubber parts and a metal ring. ANYWAY, I've become kind of an expert on this. It's not necessary to remove the hood. Leave the hood down while you unbolt the acuator and push it out of the bracket, laying it down at the bottom of the radiator. You can then open the hood to gain access. Also, disconnect the springs before you lift the lights to work on, and lower the lights at the end when you reconnect them (less tension). It's REAL easy to do. The kits come with instructions.
[Modified by 79MakoL82, 7:08 PM 3/17/2002]
This is exactly what mine did. The fact that they make an attempt tell you two things: 1) That there is vaccum getting to the actuators and 2) that your relays are working. Both times this happend to me, it was the acuator seal. You can buy the kits form Eckler's or any of the Vette places but they're not particularly cheap (as most old Vette parts are not). It's like $24 for a couple of rubber parts and a metal ring. ANYWAY, I've become kind of an expert on this. It's not necessary to remove the hood. Leave the hood down while you unbolt the acuator and push it out of the bracket, laying it down at the bottom of the radiator. You can then open the hood to gain access. Also, disconnect the springs before you lift the lights to work on, and lower the lights at the end when you reconnect them (less tension). It's REAL easy to do. The kits come with instructions.
[Modified by 79MakoL82, 7:08 PM 3/17/2002]
