Vacuum issues 1970 corvette
Thread Starter
Instructor
Joined: Oct 2010
Posts: 211
Likes: 3
From: Moscow Mills Missouri
Vacuum issues 1970 corvette
I have been troubleshooting my vacuum system for over a week. Is their anyone I could call to talk to on what I have done so far. Everything will work if I by pass the vacuum tank tank and put vacuum to the correct hose for the headlights or cowl. The headlights will not go down. Seems like they are deadheaded and they won't come down manually. I plugged off two ports on the vacuum tank and plugged my vacuum pump hose into the third port and it does hold 20 lbs of vacuum after 45 seconds.When I hook everything up correctly I only have 12 lbs of vacuum. Everything related to the vacuum system is brand new. I know brand new means nothing. Can someone help me. like I said I wish I could talk to someone who know the system.
Thanks for your help,
Thanks for your help,
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
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From: New Braunfels Texas
Thread Starter
Instructor
Joined: Oct 2010
Posts: 211
Likes: 3
From: Moscow Mills Missouri
Thanks.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
What "vacuum pump"? Has someone added a vacuum pump to your system? Perhaps the vacuum pump has an internal failure and won't hold vacuum level.
All the C3 cars built by General Motors had only one 'vacuum pump'....the car's engine.
All the C3 cars built by General Motors had only one 'vacuum pump'....the car's engine.
Thread Starter
Instructor
Joined: Oct 2010
Posts: 211
Likes: 3
From: Moscow Mills Missouri
I use a electric vacuum pump to troubleshoot the vacuum system and to check valves WITHOUT having to run the motor for hours.
My electric vacuum pumps works fine.
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Pro
Joined: Sep 2018
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From: Chicago, IL
just a long shot i had a problem with mine, turns out that little vac switch behind the dash that has 2 hoses and a electrical plug, the vac hole was plugged with who knows what, cleaned out out, then everything worked.
Thread Starter
Instructor
Joined: Oct 2010
Posts: 211
Likes: 3
From: Moscow Mills Missouri
Thread Starter
Instructor
Joined: Oct 2010
Posts: 211
Likes: 3
From: Moscow Mills Missouri
I have been troubleshooting my vacuum system for over a week. Is their anyone I could call to talk to on what I have done so far. Everything will work if I by pass the vacuum tank tank and put vacuum to the correct hose for the headlights or cowl. The headlights will not go down. Seems like they are deadheaded and they won't come down manually. I plugged off two ports on the vacuum tank and plugged my vacuum pump hose into the third port and it does hold 20 lbs of vacuum after 45 seconds.When I hook everything up correctly I only have 12 lbs of vacuum. Everything related to the vacuum system is brand new. I know brand new means nothing. Can someone help me. like I said I wish I could talk to someone who know the system.
Thanks for your help,
Thanks for your help,
THANKS DAVE.
Here are a few pics of the ground up body off restoration on my 1970 LT1
Thread Starter
Instructor
Joined: Oct 2010
Posts: 211
Likes: 3
From: Moscow Mills Missouri
