Hello,

Some "Y's" had dual action fuel pumps, one side for fuel & the other vacuum for wipers etc.  Does anyone know how much vacuum a new or rebuilt pump of this design could pull?  I was thinking if it could pull enough vacuum I could use one for a new vacuum/power assisted brakes system.  I have not installed my new engine yet but with it's cam specs of .450" lift (with 1.5:1 rockers) 288* adv. dur. and 238* @ .050 with 112* lobe centers the engine may not make enough vacuum required for the brakes.

Your help would be appreciated.  Thanks!

   

1956 F100 Big Window 309ci Y-block,  1956 F100 small window 272ci Y-block

Greg.  Mountains of North Eastern CA

I believe you may be out of luck on this. One is for wipers and the other is for the vacuum on the distributor. Dont believe thats enough for the brakes. 

55Birdman  Hickory NC

If you check some of the aftermarket brake parts suppliers you should find a vacuum resovoir for just the purpose you are asking about.

  

I once measured the vacuum at the pump, I believe it was 10".  Not enough vacuum nor volume to actuate a brake booster.

John - "The Hoosier Hurricane"

I would think that at times your engine would pull enough vacuum to pull down a vacuum tank to operate the brakes. If not, you might have to use something like a Wabco pump like is used on Diesels.

Kenneth

Fredricksburg, Texas

I say drop the motor in and see how it works. I have a friend running power brakes with an engine that has 11" hg at idle and they seem to work fine.


Lawrenceville, GA

Ive got the OE power brake booster on my 56, plumbed into the back of the intake manifold.  I have a bigger cam that pulls between 13-14" at idle, and the brakes work OK. A little more boost would be nice, but its still a noticeable improvement.

Ron Grove

Wauconda, IL

If you want the best setup for a big cammed engine use a hydra-boost. Cost is more than a vacuum boost setup. You will need a Saginaw pump. Mummert sells the brackets to mount the pump on a y-block.



http://www.tallonhydraulics.com/

marv

Thanks everyone for the replies.  I suspected it would not be enough but I wasn't sure so I had to ask.  Once I have the new engine in I will hook it up see how it goes.  I don't have a vaccum gauge so I will have to go by feel.  If I have to, I will get a tank or an electric pump.  I was just hoping for the easy solution.

Thanks again

   

1956 F100 Big Window 309ci Y-block,  1956 F100 small window 272ci Y-block

Greg.  Mountains of North Eastern CA