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12/20/2021 10:43 AM  #1


1966 mustang power brake booster problem.

Hey everyone. I have a mustang Steve cable clutch kit I bought and got the power booster with it.

I had my car in the shop for an alignment and they said my booster was leaking and needs to be replaced when I have a chance. I didn’t think to much of it. Then yesterday when I took the car out of the garage for a spin my rear brakes locked up when I pushed the brakes. I pulled it back to the house and popped the hood and it looks like it’s hissing around the grommet where the vacuum line connects to the booster. I zip tied the vacuum line back towards the wire look on the fire wall and that seemed to stop the hissing and the brakes didn’t lock up again. But now it’s stalling out on me when coming to a stop unless I rev it up.

Does this sound like it could be related to the booster?  Does anyone know what type of booster I can get to replace mine. From what I remember it should be a fox body one but when I look them up they are big ones and the one I have is the thin type. Any help would be appreciated

Thanks.

 

12/20/2021 1:11 PM  #2


Re: 1966 mustang power brake booster problem.

Easy enough to diagnose.  Disconnect the booster and plug the line then see if it no longer stalls.  If not I'd say you're booster is leaking internally and the booster is the issue.  The Fox booster is a pretty good size booster.  Its definitely not thin. 

 

12/20/2021 1:34 PM  #3


Re: 1966 mustang power brake booster problem.

It’s only stalling when coming to a stop from driving. Unless I rev it up before stopping then it doesn’t stall out.  It’s fine when just sitting. Running.  I take it I can’t drive it with it disconnected as I wouldn’t have brakes except for one or 2 presses of the pedal right.

Last edited by Evan (12/20/2021 1:35 PM)

     Thread Starter
 

12/20/2021 1:50 PM  #4


Re: 1966 mustang power brake booster problem.

No, you just won't have power assist.  The pedal will be hard, but you will still have brakes.  I wouldn't take in on the highway like that, but through the neighborhood, at slow speed or something. 

It sounds like the leak only occurs when you press the pedal, and creates a vacuum leak causing it to stall. 
 

 

12/20/2021 6:33 PM  #5


Re: 1966 mustang power brake booster problem.

You can order the new exact correct booster from www.mustangsteve.com or take your chances at OReilly or Autozone with a rebuilt one out of a 87-93 Mustang four cylinder. The one from MustangSteve will have the more desirable adjustable output shaft.  There were three different foxbody boosters.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

12/20/2021 7:53 PM  #6


Re: 1966 mustang power brake booster problem.

Oh awesome I didn’t know you sell them individually.  I’ll gladly get it from you thanks. Are they in stock?

     Thread Starter
 

12/20/2021 8:47 PM  #7


Re: 1966 mustang power brake booster problem.

Evan wrote:

Oh awesome I didn’t know you sell them individually.  I’ll gladly get it from you thanks. Are they in stock?

Take a look at,  mustangsteve.com

 

12/21/2021 1:29 AM  #8


Re: 1966 mustang power brake booster problem.

Thanks everyone. Looks like I’ll be needing a new one. I got a new one ordered through mustangsteve.com

     Thread Starter
 

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