Vacuum ?'s inside
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
Vacuum ?'s inside
When i rebuilt the 454 i put in a larger cam. Now i don't have vacuum at idle. And my brake peddle goes clear to the floor and the head lights don't go up and down when they should.
I replaced all the brakes last summer so they're all good.
Do they make a vacuum can? Or booster? What have you guys done to help the problem?
Thanks
I replaced all the brakes last summer so they're all good.
Do they make a vacuum can? Or booster? What have you guys done to help the problem?
Thanks
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
you should already have a Reservoir,
that is exactly why I did not put a huge cam in my 454.
they make an electric vacuum pump, you might need to go that route.
however a lot of guys say they run big cam's with little to no problem.
to truely answer your question you need to put a gauge on,
and ensure you have no leaks. 69VETT
that is exactly why I did not put a huge cam in my 454.
they make an electric vacuum pump, you might need to go that route.
however a lot of guys say they run big cam's with little to no problem.
to truely answer your question you need to put a gauge on,
and ensure you have no leaks. 69VETT
Last edited by 69Vett; May 21, 2009 at 09:01 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
If you had no manifold vacuum at idle, the engine wouldn't be running. I suspect you have a big vacuum leak somewhere. How are you measuring the vacuum level? What vacuum lines have you disconnected and/or capped?
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
I just put the gauge on the carb, and when i gave it gas the gauge would go to the green.
And i don't think i touched any of the lines. I guess i'll have to look it over for a leak or something i missed.
And i don't think i touched any of the lines. I guess i'll have to look it over for a leak or something i missed.
Burning Brakes
Joined: May 2008
Posts: 1,165
Likes: 24
From: Boston MA
The most likely culprit for a leak is the supply line to the heater. For a 1970, this line is T'd into the supply line to the wiper door rely, that T is easily broken, and you would have a massive leak.
But I am not sure if a '73 works the same way.
But I am not sure if a '73 works the same way.
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Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
When i rebuilt the 454 i put in a larger cam. Now i don't have vacuum at idle. And my brake peddle goes clear to the floor and the head lights don't go up and down when they should.
I replaced all the brakes last summer so they're all good.
Do they make a vacuum can? Or booster? What have you guys done to help the problem?
Thanks
I replaced all the brakes last summer so they're all good.
Do they make a vacuum can? Or booster? What have you guys done to help the problem?
Thanks
Low vac to the brake booster results in a hard pedal.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
I can see why you would expect that everything brake related was good at this point, but there is air in your system somewhere.