Vacuum leaks
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,137
Likes: 4,247
From: US-PNW
Providing the year of your car is always helpful to point you in the right direction. That said, the main vacuum hose, right off the engine's intake manifold that runs to the vacuum tank, is likely the best place to start.
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,335
From: North of Toronto - Ontario
Does the smoke machine put out enough pressure to push through the vacuum system on a vette? I'm thinking you can't really test it under vacuum so you'd have to pump the smoke into the system instead? The main vacuum source is pulled from the intake manifold, through the filter and check-valve so if you removed the hoses from the check valve and hooked the smoke machine on them I guess it should fill the lines with smoke and you'd see where it was leaking out at the relays or actuators.. I don't think there is any way of making the relays work without vacuum...
Honestly, I'm not sure there's a real benefit to using a smoke machine to test the vacuum system is there? Maybe I'm missing something
https://www.corvette-101.com/vacuum.htm
M
Honestly, I'm not sure there's a real benefit to using a smoke machine to test the vacuum system is there? Maybe I'm missing something
https://www.corvette-101.com/vacuum.htm
M
Safety Car
Joined: Oct 2007
Posts: 4,222
Likes: 1,078
From: South Florida
Pressure test the intake. Look up boost pressure leak test. View a few videos to see how its done. On an NA engine its much simpler and easy to do.
You can't rely on smoke because some leaks require pressure to expose. For example intake gaskets may only leak at -5psi or +5psi. Psi can be negative or positive with respect to atmosphere. For example 1" Hg of vacuum is equal to -0.491154 PSI
You can't rely on smoke because some leaks require pressure to expose. For example intake gaskets may only leak at -5psi or +5psi. Psi can be negative or positive with respect to atmosphere. For example 1" Hg of vacuum is equal to -0.491154 PSI
