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need help w/ vacuum



Hey all,
We need help with our vacuum system. We've been working on the 78 all day, wheel bearings, polishing wheels and just installed a metal flex fan. (So far I like it, has no excess noise but sure moves the air! Can't wait to take her for a drive to watch the temp, just sitting in the garage, the temp sat at 185...and it hasn't seen that in ages!)
We can hear a vacuum leak at the carburator (hissing). We also know the headlight actuator diaphrams need replacing. We suspect the vacuum canister needs replacing, too. Since we still haven't painted our bookcases, and the books are still packed away....including the Vette manuals :cry would someone please email me a diagram of the vacuum system or direct me to a website or homepage that shows this system?
Thanks, Silver

Check the carb..


With the car running you can cover the mouth of the carb, if it is the carb leaking it will run a little rough but continue to run. Also spray a little 5-56 around the carb and see it the idle smooths out. Quads are pretty notorious for sucking part of the gasget material..

I would start there, I can't scan anything right now... I can't get to the program because of a virus... :cry

Have you tried pinching off vacuum lines? And don't over look the ones under the dash.. two go to the little pull down switch and two go to the headlight switch..


Hi Bud,
Thanks for the reply, and I'm sorry your computer is still "gone fishing" w/ worms.... have you gone shopping for a new one yet?
We did pinch off lines, but the carb still hissed. We will try your ideas tonight.
Thanks, Heidi
Hi Heidi,

Here's a picture af a vacuumdiagram hope it helps
It's the only one I have(sorry)
All the best.



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