adding a vacuum pump
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,692
Likes: 157
From: Miami, FL
adding a vacuum pump
On my 70 BB I am interested in adding a vacuum pump just to be sure I have vacuum at idle for brake booster and lights & wiper cover. I'm looking for recommendations for a reliable electric vacuum pump that I can mount somewhere out of sight and put that system aside for the time being. I will continue to work on solving my vacuum issues, but need something I can rely on for the near term as I need to use the car.
Safety Car
Joined: May 2004
Posts: 4,347
Likes: 1,576
From: los altos hills california
I once researched this but never did anything. Here's a forinstance:
https://www.corvetteforum.com/forums...onversion.html
https://www.corvetteforum.com/forums...onversion.html
Last edited by ignatz; Sep 2, 2025 at 07:27 PM.
2026 Loser of the Year
Joined: Sep 2013
Posts: 36,559
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From: New Or-leens Loo-z-anna
This method might save you $$$.......(Members please advise if the method below will not work)
"Ultimately, a modified AC compressor can produce 28Hg (28 lbs.) be a very effective and low-cost alternative for applications,"
You could wire the a/c clutch to an12VDC vacuum switch mounted on the vacuum reservoir
so the unit would engage the clutch at a level set by you. The unit would not run constantly, but would keep the HG level constant.
You can buy a a/c compressor and hose with bracket for less than $50 at a late model salvage yard.
Get a friend to modify the bracket to fit your engine if you don't have that skill level.
"Ultimately, a modified AC compressor can produce 28Hg (28 lbs.) be a very effective and low-cost alternative for applications,"
You could wire the a/c clutch to an12VDC vacuum switch mounted on the vacuum reservoir
so the unit would engage the clutch at a level set by you. The unit would not run constantly, but would keep the HG level constant.
You can buy a a/c compressor and hose with bracket for less than $50 at a late model salvage yard.
Get a friend to modify the bracket to fit your engine if you don't have that skill level.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,692
Likes: 157
From: Miami, FL
Interesting idea with the AC pump, but I would rather not put another belt on the engine. There are a lot of options for electric pumps and it's been mentioned here before. I figure there are some already completed that may have some advice on those.
Is my vette stock?? HAHA
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From: Im not allowed to tell you
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I had 2 different ones when I had about 13 to 15 inches i used a little Hella pump that came with a remote shutoff at a set point, it was loud but small. When I put in a different induction system that had only 10 inches of vacuum I got a Leeds vacuum pump that is designed for brakes only. It came with a plastic cover and it was huge. I ended up just running the pump. If yo can hid them in front of the radiator or all the way in back near the spare tire tub but you will be running a long vacuum line. Its quieter than the Hella vacuum pump. I still use that fo rmy headlights
Safety Car
Joined: May 2004
Posts: 4,347
Likes: 1,576
From: los altos hills california
On my 70 BB I am interested in adding a vacuum pump just to be sure I have vacuum at idle for brake booster and lights & wiper cover. I'm looking for recommendations for a reliable electric vacuum pump that I can mount somewhere out of sight and put that system aside for the time being. I will continue to work on solving my vacuum issues, but need something I can rely on for the near term as I need to use the car.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,692
Likes: 157
From: Miami, FL
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Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,692
Likes: 157
From: Miami, FL
Looking at this one from amazon. Seems a little large at 10-1/2" overall length. Maybe hiding in the rear is possible. I hate adding something like this to a mostly unmodified and original car but I need this stuff to work and don't have much time to try other solutions.
Heel & Toe
Joined: Jun 2025
Posts: 18
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From: Southern Ontario
I'll mention that many modern vehicles are coming with vacuum pumps from the factory due to low vacuum at idle (increases pumping efficiencies, better emissions numbers). Caravans and Wranglers come to mind, and they're electric, fairly small and quiet. Just something to think about.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,692
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From: Miami, FL
I haven't opened the box yet. With timing adjusted it is behaving a little better, but the wiper door is still opening when idling. I'm going to trouble shoot the vacuum system next and go from there.
Thread Starter
Drifting
Joined: Jun 2007
Posts: 1,692
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From: Miami, FL
I ended up returning the pump. The check valve at the reservoir was found to be passing air in both directions. So I need to replace that before and recheck the system before doing anything dramatic.
Pro
Joined: Dec 2010
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I had the same idea as I intend to install a decent cam in the 350 small block that will be getting rebuilt. I have been dealing with the original, nonfunctioning wiper cover today. I also started checking for vacuum leaks and dug into the headlight vacuum system. Then I found an electric conversion kit for the headlight door system for less than $100 on Ebay. They also sell an electric wiper cover conversion for about $390 on Ebay and that manufacturer's kit has been talked about on this forum before. His kit has good reviews. I know this may not be the answer that you are looking for, but before I spend good money for an electric vacuum pump, I would think removing some of the load on the OEM vacuum system might help send more volume to the brake booster.
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
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Thats not how vacuum works. If you have 10 inches of vacuum, thats it. Everywhere sees the 10 inches. He has to either add pumps to increase it or go electric. Leeds makes an electric pump that is brake booster only and i saw someone else had a link to another company. The brakes need a higher volume vacuum pump for quicker recovery. Vacuum accessories are one and done ....turn on headlights , doors open and they stay there for the trip..
