vacuum hookup for power brakes

Johnnydidd

Johnnydidd

Well-known member
I just bought a old style vacuum brake booster for my 56 Merc, where do you hook up the vacuum for the booster and do I need to use the vacuum tank?
 
Pictures of the parts you just got will help with providing a better answer.

The vacuum line for the brake booster comes thru a large-ish (3/8?) line from a fitting on the intake manifold or at the base of the carb. Do you have an ecz-a or ecz-b intake manifold?
Some intake manifolds have a vacuum port in front of the carb.
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Correct what dmsfrr said. In '56 there is a brass fitting in the back of the carb whether the 312 came with a Holley teapot or a Carter WCFB. The fitting for cars with power brakes had three holes for vacuum lines. One small line to the fuel pump vacuum pump, one small line to the dual diaphragm distributor, and a large line in the back of the fitting for the power brake booster. Cars W/O power brakes used a different fitting with only the two small holes. Pretty hard to find the 3-hole fittings, but could always plumb in a line for the power brakes with a "T" somehow.

The '57 intakes had the hole for power brakes in the back as in Dmsfrr's photo.
In 1955, there was a fitting in the manifold in front of the carb for the power brakes.

Sal
 
When I had the manifold off I drilled and tapped a 1/4 pipe thread behind the carburetor is that large enough to handle the power brakes
 
Johnnydidd said:
When I had the manifold off I drilled and tapped a 1/4 pipe thread behind the carburetor is that large enough to handle the power brakes
Click to expand...
Smaller than any factory power brake port. Most cars don't use a can for the brakes unless the cam is radical. You can always add one after you drive it if you think it needs it.
 
The I.D. of the power brake hose fitting in the '55 intake I have is 3/8". The pipe thread is 1/2". So sounds like the fitting you have is a little small (1/4" I.D.).

Also, don't remember a car from the factory back then that ever used a vacuum tank.

Sal
 
Most any auto parts store should have a brass fitting to
adapt from 1/4 pipe thread to a 3/8 hose snout.







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scicala said:
The I.D. of the power brake hose fitting in the '55 intake I have is 3/8". The pipe thread is 1/2". So sounds like the fitting you have is a little small (1/4" I.D.).

Also, don't remember a car from the factory back then that ever used a vacuum tank.

Sal
Click to expand...

57 Fords had a tank on the drivers side inner fender (I have the set up for my Retractable) as does my 58 Edsel Pacer.
 
The vacuum canister is basically a device for the storage of nothing. It keeps a reserve of nothing so that your brakes and other vacuum operated systems will work properly under low vacuum conditions, i.e., repeated use of the brakes in short period of time, hard acceleration or if the engine dies. I would install it.
 
Lanny said:
Most any auto parts store should have a brass fitting to
adapt from 1/4 pipe thread to a 3/8 hose snout.


The trouble with that is that the I.D. of the hole in the 1/4" pipe fitting is still only 1/4" and not 3/8".

If the carb that's on the car now has a large vacuum nipple on it for maybe PCV, then that could be used for the power brake booster.

Sal
Click to expand...
 
Can I use the same vacuum hook up I use for my pcv valve, it is a spacer mounted under the carburetor with 3/8 tube
 
"If the carb that's on the car now has a large vacuum nipple on it for maybe PCV, then that could be used for the power brake booster.

Sal "



Above, is what I put in post #11.

Sal
 
I think it should be OK, since the PCV valve has a small restriction in it and just passes enough vacuum to keep the crankcase evacuated of oil fumes. But probably best to have a separate fitting for each.

Sal
 
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