Headlight vacuum canister
Thread Starter
Drifting
Joined: May 2011
Posts: 1,345
Likes: 0
Headlight vacuum canister
Hello. I just bought an '81 Corvette and have not learned to work on it yet. The headlights do not come up and mechanic diagnosed a leaking vacuum canister. He wanted to bill me to replace it, I said no thanks. I can see it in the car nose, it does not look so hard to replace. I'd rather not waste time goofing around if someone could give tips on replacement. It's probably easy if you know how and I just don't know.
I bought a Clymer shop manual but it's not very informative.
Thanks!
I bought a Clymer shop manual but it's not very informative.
Thanks!
Racer
Joined: Feb 2007
Posts: 271
Likes: 25
From: Buena Vista Colorado
The problem may or may not be your vacuum canister. If it is leaking so badly that your lights won't come up, you likely would have a rough running motor as well because you would have a lean air-fuel mixture.
Here's a link to a sticky posting I wrote that has helped some folks figure out some of their their headlight vacuum problems:
How Your Headlight Vacuum System Works
It's not a complicated system, but neither is it intuitive until you study it and work with it a bit. Get yourself a low cost hand operated vacuum pump and have at it.
BTW: Do yourself a favor and get an Assembly Information Manual (AIM) for your '81. It's available from forum vendor sponsors. And buy a real Chevrolet shop manual for the '81 Corvette. I found both the AIM and the Chevrolet shop manual for my '78 on ebay, and they have saved me tons of time & $$$.
Here's a link to a sticky posting I wrote that has helped some folks figure out some of their their headlight vacuum problems:
How Your Headlight Vacuum System Works
It's not a complicated system, but neither is it intuitive until you study it and work with it a bit. Get yourself a low cost hand operated vacuum pump and have at it.
BTW: Do yourself a favor and get an Assembly Information Manual (AIM) for your '81. It's available from forum vendor sponsors. And buy a real Chevrolet shop manual for the '81 Corvette. I found both the AIM and the Chevrolet shop manual for my '78 on ebay, and they have saved me tons of time & $$$.
Last edited by 78IndyPace; Jun 5, 2011 at 10:54 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
I read the advice of "Get yourself a hand vacuum pump" all the time. Exactly what can you do with the hand vacuum pump that you can't find out with a running engine? The hand pumps don't generate any real 'volume' of vacuum (if you can actually have a 'volume' of nothin???), so what can it do for you?
Note: This is not meant to be a 'challenge'; it is a legitimate question and I want to learn, if there is something of value here.
Note: This is not meant to be a 'challenge'; it is a legitimate question and I want to learn, if there is something of value here.
Melting Slicks
Joined: Jun 2005
Posts: 2,239
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From: Palatine, Peoples Republic of Illinois
St. Jude Donor '09-'10-'11-12-'13-'14-'15-'16-'17-‘18
NCM Sinkhole Donor
Usually when you're working on the vacuum system you will be working on an isolated part of the system so you don't need a lot of volume. The hand pump allows you to work without the noise, heat and fumes from running the engine. It's also a lot safer (no fans, belts, electricity etc.). I got mine form Sears. Good investment. You also need to get a the AIM for your year. That should tell you most of what you need. Hope this helps. 
Jim
Jim
Race Director
Joined: Jul 2001
Posts: 15,892
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Much cheaper and more effective to run a longggggg piece of vacuum hose from another car outside the garage. The vacuum pump are helpful whne bench checking individual components, not trying to activate the entire system at the same time.
Race Director
Joined: May 2006
Posts: 16,528
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From: Dayton, Ohio
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Race Director
Joined: May 2006
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From: Dayton, Ohio
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Hello. I just bought an '81 Corvette and have not learned to work on it yet. The headlights do not come up and mechanic diagnosed a leaking vacuum canister. He wanted to bill me to replace it, I said no thanks. I can see it in the car nose, it does not look so hard to replace. I'd rather not waste time goofing around if someone could give tips on replacement. It's probably easy if you know how and I just don't know.
I bought a Clymer shop manual but it's not very informative.
Thanks!
I bought a Clymer shop manual but it's not very informative.
Thanks!
Le Mans Master
Joined: Mar 2008
Posts: 5,948
Likes: 72
From: Oxford MA-----You just lost the game!!!!
I read the advice of "Get yourself a hand vacuum pump" all the time. Exactly what can you do with the hand vacuum pump that you can't find out with a running engine? The hand pumps don't generate any real 'volume' of vacuum (if you can actually have a 'volume' of nothin???), so what can it do for you?
Note: This is not meant to be a 'challenge'; it is a legitimate question and I want to learn, if there is something of value here.
Note: This is not meant to be a 'challenge'; it is a legitimate question and I want to learn, if there is something of value here.
A cheap little hand vacuum pump is an awesome little tool. You can use it as a vacuum gauge when tuning the idle screw on your carb, and if you do a google search on "using a vacuum gauge to diagnose engine" you will find numerous articles on how to use a vacuum guage to tell quite a few different things about an engine. You can use a hand vacuum pump to bleed brakes. You can use it to check a vacuum hose for leaks by applying a little vacuum and observing the gauge. All kids of stuff.
Scott
