Vacuum Loss - Team Camaro Tech
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post #1 of 29 (permalink) Old Sep 8th, 14, 08:02 PM Thread Starter
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Matt
 
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Vacuum Loss

I have a high lift cam in my L72. There is not enough vacuum feeding the brake booster, so my front power disc brakes do not work.

Anybody have a recommendation? Vacuum reservoir? Electric vacuum pump?

Are electric vacuum pumps noisy?
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post #2 of 29 (permalink) Old Sep 8th, 14, 09:05 PM
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Don
 
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Re: Vacuum Loss

How much vacumn does the motor make? Pulling off what source? Stock cam?
If you suspect you have a hole in the booster diaphragm, you could be misunderstanding the problem. Have you verified the booster will hold vac? You should also have a vacumn check valve at the booster , feeding the line. That thing sometimes cracks and leaks.

Don
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Zdld17:69 Z/RS,306, NOR141111, 9N554XXX, 12A, X3G, 59/59,723, AFR 195,CCC282/290HR, TKO 600, BU1122B1E Owner since Dec 1968

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post #3 of 29 (permalink) Old Sep 8th, 14, 11:26 PM
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Steps
 
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Re: Vacuum Loss

Quote:
There is not enough vacuum feeding the brake booster, so my front power disc brakes do not work.
When do they not work?
When u are coming up to an intersection with engine braking and high vaccuum?
Or when u are stilling in your driveaway pumping the brakes?
Or when u have filled up the gas tank and idling across the forecourt to the kerb to enter the street?

Basically in the real practical world at idle u dont need any vaccuum or boosted brakes cuse unles u are on a hill with the E brake off u have manual brakes... all other time u have high rpms high vaccuum and usually engine braking which is even higher vaccuum still.

Anything over 5 to 7" at idle is sufficient.. and if u need more ..at idle...then dial the idle advance and the idle circuits in carb to best STABLE idle... issue solved.

My Spelling is not incorrect...it is creative

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post #4 of 29 (permalink) Old Sep 9th, 14, 12:18 PM Thread Starter
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Re: Vacuum Loss

Quote:
Originally Posted by zdld17 View Post
How much vacumn does the motor make? Pulling off what source? Stock cam?
If you suspect you have a hole in the booster diaphragm, you could be misunderstanding the problem. Have you verified the booster will hold vac? You should also have a vacumn check valve at the booster , feeding the line. That thing sometimes cracks and leaks.
Yes, pulling off high lift cam. Booster works. Check valve is fine.
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post #5 of 29 (permalink) Old Sep 9th, 14, 01:35 PM
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Re: Vacuum Loss

Hydro-Boost is the best solution if you have a power steering pump. The next best would be a mechanical vacuum pump off of a modern diesel engine where you will have to make your own custom brackets to mount it to your motor based upon the length of a belt that fits the application. Either that or go for a diesel pick-up before the mechanical pumps that used an electric vacuum pump.

Cadillac used an electric vacuum pump back in the early sixties but it was a supplemental pump to the engine vacuum and not designed to pull a hard vacuum like the diesel pump is. Diesels don't have manifold vacuum because they are open to the atmosphere to maximize cylinder filling (with direct injection there is no mixing of fuel and air out side of the cylinder.

If you have a street strip car that is more strip than street you could install a Moroso vacuum pump and tap into that for brake booster vacuum and still get better ring seal. Of course if it where mine I would loose the power assist and go with manual brakes.

Larger Dave
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post #6 of 29 (permalink) Old Sep 9th, 14, 01:48 PM Thread Starter
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Matt
 
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Re: Vacuum Loss

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Originally Posted by Larger Dave View Post
Hydro-Boost is the best solution if you have a power steering pump. The next best would be a mechanical vacuum pump off of a modern diesel engine where you will have to make your own custom brackets to mount it to your motor based upon the length of a belt that fits the application. Either that or go for a diesel pick-up before the mechanical pumps that used an electric vacuum pump.

Cadillac used an electric vacuum pump back in the early sixties but it was a supplemental pump to the engine vacuum and not designed to pull a hard vacuum like the diesel pump is. Diesels don't have manifold vacuum because they are open to the atmosphere to maximize cylinder filling (with direct injection there is no mixing of fuel and air out side of the cylinder.

If you have a street strip car that is more strip than street you could install a Moroso vacuum pump and tap into that for brake booster vacuum and still get better ring seal. Of course if it where mine I would loose the power assist and go with manual brakes.

Larger Dave
Thank you Dave.
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post #7 of 29 (permalink) Old Sep 9th, 14, 03:05 PM
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Re: Vacuum Loss

why not make/buy a vacuum can
I made one out of a small propane tank and it works great
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post #8 of 29 (permalink) Old Sep 9th, 14, 05:44 PM
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Re: Vacuum Loss

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Originally Posted by flat tire View Post
why not make/buy a vacuum can
I made one out of a small propane tank and it works great
While thinking out loud, Do you have vacumn head lamp doors, if not , that vacumn can will fit neatly on the fender and look stock and its near the booster.

But really, I don't think cheating the brake booster of its necessary vacumn. Ready to go hydra-booster if you have a ps pump?

Don
TC # 349
Zdld17:69 Z/RS,306, NOR141111, 9N554XXX, 12A, X3G, 59/59,723, AFR 195,CCC282/290HR, TKO 600, BU1122B1E Owner since Dec 1968

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post #9 of 29 (permalink) Old Sep 9th, 14, 06:24 PM
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Re: Vacuum Loss

Quote:
Originally Posted by zdld17 View Post
While thinking out loud, Do you have vacumn head lamp doors, if not , that vacumn can will fit neatly on the fender and look stock and its near the booster.

But really, I don't think cheating the brake booster of its necessary vacumn. Ready to go hydra-booster if you have a ps pump?
no headlight doors
here is a picture.
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post #10 of 29 (permalink) Old Sep 9th, 14, 07:26 PM Thread Starter
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Matt
 
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Re: Vacuum Loss

Quote:
Originally Posted by zdld17 View Post
While thinking out loud, Do you have vacumn head lamp doors, if not , that vacumn can will fit neatly on the fender and look stock and its near the booster.

But really, I don't think cheating the brake booster of its necessary vacumn. Ready to go hydra-booster if you have a ps pump?
No vacuum head lamp doors. Yes, I do have a PS pump.

Thanks for the pic.
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post #11 of 29 (permalink) Old Sep 9th, 14, 07:42 PM Thread Starter
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Re: Vacuum Loss

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Originally Posted by flat tire View Post
no headlight doors
here is a picture.
Think this will fit there with voltage regulator and horn relay in that area?
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post #12 of 29 (permalink) Old Sep 9th, 14, 08:36 PM
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Don
 
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Re: Vacuum Loss

Quote:
Originally Posted by Matt69SS View Post
No vacuum head lamp doors. Yes, I do have a PS pump.

Thanks for the pic.
Well ,if you have a ps pump, then all you need to do is decide hydra booster.

Don
TC # 349
Zdld17:69 Z/RS,306, NOR141111, 9N554XXX, 12A, X3G, 59/59,723, AFR 195,CCC282/290HR, TKO 600, BU1122B1E Owner since Dec 1968

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post #13 of 29 (permalink) Old Sep 10th, 14, 04:50 AM
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Re: Vacuum Loss

Quote:
Originally Posted by Matt69SS View Post
Think this will fit there with voltage regulator and horn relay in that area?
yes . there is plenty of room for the V.R. in its original place
I moved mine closer to the outer fender to hide it
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post #14 of 29 (permalink) Old Sep 10th, 14, 05:53 AM
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Re: Vacuum Loss

HydraBoost is found on diesel powered pick-up trucks and vans and on most medium duty trucks and buses if they didn't have air brakes. Here is a Hydraboost installed along with a hydraulic clutch (which why there is a hose going into the brake reservoir):.



Here is the part you need off the donor vehicle:



Big Dave
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post #15 of 29 (permalink) Old Sep 10th, 14, 08:10 AM Thread Starter
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Matt
 
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Re: Vacuum Loss

Thanks everyone. I appreciate it.
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